global: Rename SPL_ to XPL_

Use XPL_ as the symbol to indicate an SPL build. This means that SPL_ is
no-longer set.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/arm920t/Makefile b/arch/arm/cpu/arm920t/Makefile
index 5ac3740..06456fe 100644
--- a/arch/arm/cpu/arm920t/Makefile
+++ b/arch/arm/cpu/arm920t/Makefile
@@ -9,6 +9,6 @@
 
 # some files can only build in ARM mode
 
-ifdef CONFIG_$(SPL_)SYS_THUMB_BUILD
+ifdef CONFIG_$(XPL_)SYS_THUMB_BUILD
 CFLAGS_cpu.o := -marm
 endif
diff --git a/arch/arm/cpu/arm926ejs/Makefile b/arch/arm/cpu/arm926ejs/Makefile
index 7551388..750cb94 100644
--- a/arch/arm/cpu/arm926ejs/Makefile
+++ b/arch/arm/cpu/arm926ejs/Makefile
@@ -17,7 +17,7 @@
 
 # some files can only build in ARM or THUMB2, not THUMB1
 
-ifdef CONFIG_$(SPL_)SYS_THUMB_BUILD
+ifdef CONFIG_$(XPL_)SYS_THUMB_BUILD
 ifndef CONFIG_HAS_THUMB2
 
 CFLAGS_cpu.o := -marm
diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 0e7d769..6461f5f 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/arch/arm/cpu/armv7/Makefile
@@ -17,7 +17,7 @@
 obj-$(CONFIG_ARMV7_NONSEC) += exception_level.o
 endif
 
-ifneq ($(CONFIG_$(SPL_)SKIP_LOWLEVEL_INIT),y)
+ifneq ($(CONFIG_$(XPL_)SKIP_LOWLEVEL_INIT),y)
 obj-y	+= lowlevel_init.o
 endif
 
diff --git a/arch/arm/cpu/armv8/Makefile b/arch/arm/cpu/armv8/Makefile
index 722ec89..c5f568e 100644
--- a/arch/arm/cpu/armv8/Makefile
+++ b/arch/arm/cpu/armv8/Makefile
@@ -9,7 +9,7 @@
 ifndef CONFIG_$(SPL_TPL_)TIMER
 obj-$(CONFIG_SYS_ARCH_TIMER) += generic_timer.o
 endif
-ifndef CONFIG_$(SPL_)SYS_DCACHE_OFF
+ifndef CONFIG_$(XPL_)SYS_DCACHE_OFF
 obj-y	+= cache_v8.o
 obj-y	+= cache.o
 endif
@@ -32,7 +32,7 @@
 else
 obj-$(CONFIG_ARCH_SUNXI) += fel_utils.o
 endif
-obj-$(CONFIG_$(SPL_)ARMV8_SEC_FIRMWARE_SUPPORT) += sec_firmware.o sec_firmware_asm.o
+obj-$(CONFIG_$(XPL_)ARMV8_SEC_FIRMWARE_SUPPORT) += sec_firmware.o sec_firmware_asm.o
 
 ifdef CONFIG_XPL_BUILD
 obj-$(CONFIG_SPL_RECOVER_DATA_SECTION) += spl_data.o