cpu: Support querying the address width

Different CPUs may support different address widths, meaning the amount of
memory they can address. Add a property for this to the cpu_info struct.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/cpu/cpu_sandbox.c b/drivers/cpu/cpu_sandbox.c
index ff87e8a..05b384f 100644
--- a/drivers/cpu/cpu_sandbox.c
+++ b/drivers/cpu/cpu_sandbox.c
@@ -19,6 +19,7 @@
 {
 	info->cpu_freq = 42 * 42 * 42 * 42 * 42;
 	info->features = 0x42424242;
+	info->address_width = IS_ENABLED(CONFIG_PHYS_64BIT) ? 64 : 32;
 
 	return 0;
 }
diff --git a/include/cpu.h b/include/cpu.h
index 28dd48f..6b1b6b3 100644
--- a/include/cpu.h
+++ b/include/cpu.h
@@ -44,10 +44,12 @@
  *
  * @cpu_freq:	Current CPU frequency in Hz
  * @features:	Flags for supported CPU features
+ * @address_width:	Width of the CPU address space in bits (e.g. 32)
  */
 struct cpu_info {
 	ulong cpu_freq;
 	ulong features;
+	uint address_width;
 };
 
 struct cpu_ops {
diff --git a/test/dm/cpu.c b/test/dm/cpu.c
index f5f1cae..e6dc576 100644
--- a/test/dm/cpu.c
+++ b/test/dm/cpu.c
@@ -33,6 +33,7 @@
 	ut_assertok(cpu_get_info(dev, &info));
 	ut_asserteq(info.cpu_freq, 42 * 42 * 42 * 42 * 42);
 	ut_asserteq(info.features, 0x42424242);
+	ut_asserteq(info.address_width, 32);
 
 	ut_asserteq(cpu_get_count(dev), 42);