cpu: Convert the methods to use a const udevice *

These functions should not modify the device. Convert them to const so
that callers don't need to cast if they have a const udevice *.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/apollolake/cpu.c b/arch/x86/cpu/apollolake/cpu.c
index aa7a3db..0a6d2ad 100644
--- a/arch/x86/cpu/apollolake/cpu.c
+++ b/arch/x86/cpu/apollolake/cpu.c
@@ -9,7 +9,7 @@
 #include <asm/cpu_common.h>
 #include <asm/cpu_x86.h>
 
-static int apl_get_info(struct udevice *dev, struct cpu_info *info)
+static int apl_get_info(const struct udevice *dev, struct cpu_info *info)
 {
 	return cpu_intel_get_info(info, INTEL_BCLK_MHZ);
 }
diff --git a/arch/x86/cpu/baytrail/cpu.c b/arch/x86/cpu/baytrail/cpu.c
index 18e48ff..309a50a 100644
--- a/arch/x86/cpu/baytrail/cpu.c
+++ b/arch/x86/cpu/baytrail/cpu.c
@@ -150,7 +150,7 @@
 	return bclk * ((platform_info.lo >> 8) & 0xff);
 }
 
-static int baytrail_get_info(struct udevice *dev, struct cpu_info *info)
+static int baytrail_get_info(const struct udevice *dev, struct cpu_info *info)
 {
 	info->cpu_freq = tsc_freq();
 	info->features = 1 << CPU_FEAT_L1_CACHE | 1 << CPU_FEAT_MMU;
@@ -158,7 +158,7 @@
 	return 0;
 }
 
-static int baytrail_get_count(struct udevice *dev)
+static int baytrail_get_count(const struct udevice *dev)
 {
 	int ecx = 0;
 
diff --git a/arch/x86/cpu/broadwell/cpu_full.c b/arch/x86/cpu/broadwell/cpu_full.c
index 64a1cd4..706f68f 100644
--- a/arch/x86/cpu/broadwell/cpu_full.c
+++ b/arch/x86/cpu/broadwell/cpu_full.c
@@ -626,12 +626,12 @@
 	}
 }
 
-static int broadwell_get_info(struct udevice *dev, struct cpu_info *info)
+static int broadwell_get_info(const struct udevice *dev, struct cpu_info *info)
 {
 	return cpu_intel_get_info(info, INTEL_BCLK_MHZ);
 }
 
-static int broadwell_get_count(struct udevice *dev)
+static int broadwell_get_count(const struct udevice *dev)
 {
 	return 4;
 }
diff --git a/arch/x86/cpu/cpu_x86.c b/arch/x86/cpu/cpu_x86.c
index 3f2ba08..7e83051 100644
--- a/arch/x86/cpu/cpu_x86.c
+++ b/arch/x86/cpu/cpu_x86.c
@@ -26,7 +26,7 @@
 	return 0;
 }
 
-int cpu_x86_get_vendor(struct udevice *dev, char *buf, int size)
+int cpu_x86_get_vendor(const struct udevice *dev, char *buf, int size)
 {
 	const char *vendor = cpu_vendor_name(gd->arch.x86_vendor);
 
@@ -38,7 +38,7 @@
 	return 0;
 }
 
-int cpu_x86_get_desc(struct udevice *dev, char *buf, int size)
+int cpu_x86_get_desc(const struct udevice *dev, char *buf, int size)
 {
 	char *ptr;
 
@@ -52,7 +52,7 @@
 	return 0;
 }
 
-int cpu_x86_get_count(struct udevice *dev)
+int cpu_x86_get_count(const struct udevice *dev)
 {
 	int node, cpu;
 	int num = 0;
diff --git a/arch/x86/cpu/ivybridge/model_206ax.c b/arch/x86/cpu/ivybridge/model_206ax.c
index 5954a24..55f7cc2 100644
--- a/arch/x86/cpu/ivybridge/model_206ax.c
+++ b/arch/x86/cpu/ivybridge/model_206ax.c
@@ -410,14 +410,15 @@
 	return 0;
 }
 
-static int model_206ax_get_info(struct udevice *dev, struct cpu_info *info)
+static int model_206ax_get_info(const struct udevice *dev,
+				struct cpu_info *info)
 {
 	return cpu_intel_get_info(info, INTEL_BCLK_MHZ);
 
 	return 0;
 }
 
-static int model_206ax_get_count(struct udevice *dev)
+static int model_206ax_get_count(const struct udevice *dev)
 {
 	return 4;
 }
diff --git a/arch/x86/cpu/qemu/cpu.c b/arch/x86/cpu/qemu/cpu.c
index f40fb4d..9ce86b3 100644
--- a/arch/x86/cpu/qemu/cpu.c
+++ b/arch/x86/cpu/qemu/cpu.c
@@ -10,7 +10,7 @@
 #include <qfw.h>
 #include <asm/cpu.h>
 
-int cpu_qemu_get_desc(struct udevice *dev, char *buf, int size)
+int cpu_qemu_get_desc(const struct udevice *dev, char *buf, int size)
 {
 	if (size < CPU_MAX_NAME_LEN)
 		return -ENOSPC;
@@ -20,7 +20,7 @@
 	return 0;
 }
 
-static int cpu_qemu_get_count(struct udevice *dev)
+static int cpu_qemu_get_count(const struct udevice *dev)
 {
 	return qemu_fwcfg_online_cpus();
 }
diff --git a/arch/x86/include/asm/cpu_x86.h b/arch/x86/include/asm/cpu_x86.h
index ae8f4dc..4fd5f03 100644
--- a/arch/x86/include/asm/cpu_x86.h
+++ b/arch/x86/include/asm/cpu_x86.h
@@ -28,7 +28,7 @@
  * @size:	Size of string space
  * @return:	0 if OK, -ENOSPC if buffer is too small, other -ve on error
  */
-int cpu_x86_get_desc(struct udevice *dev, char *buf, int size);
+int cpu_x86_get_desc(const struct udevice *dev, char *buf, int size);
 
 /**
  * cpu_x86_get_count() - Get the number of cores for an x86 CPU
@@ -40,7 +40,7 @@
  * @return:	Number of cores if successful,
  *		-ENOENT if not "/cpus" entry is found in the device tree
  */
-int cpu_x86_get_count(struct udevice *dev);
+int cpu_x86_get_count(const struct udevice *dev);
 
 /**
  * cpu_x86_get_vendor() - Get a vendor string for an x86 CPU
@@ -53,6 +53,6 @@
  * @size:	Size of string space
  * @return:	0 if OK, -ENOSPC if buffer is too small, other -ve on error
  */
-int cpu_x86_get_vendor(struct udevice *dev, char *buf, int size);
+int cpu_x86_get_vendor(const struct udevice *dev, char *buf, int size);
 
 #endif /* _ASM_CPU_X86_H */