services/spm_deprecated: update ARM platform specific asserts

Update some asserts that refer to #defines that only occur in
ARM platforms, preventing this code to be used on other platforms.
Instead, use a platform agnostic name, and update all the existing
users.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 6281608..d1c03be 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -46,8 +46,8 @@
 		PLAT_ARM_TZC_NS_DEV_ACCESS}, 				\
 	{ARM_DRAM2_BASE, ARM_DRAM2_END, ARM_TZC_NS_DRAM_S_ACCESS,	\
 		PLAT_ARM_TZC_NS_DEV_ACCESS},				\
-	{ARM_SP_IMAGE_NS_BUF_BASE, (ARM_SP_IMAGE_NS_BUF_BASE +		\
-		ARM_SP_IMAGE_NS_BUF_SIZE) - 1, TZC_REGION_S_NONE,	\
+	{PLAT_SP_IMAGE_NS_BUF_BASE, (PLAT_SP_IMAGE_NS_BUF_BASE +	\
+		PLAT_SP_IMAGE_NS_BUF_SIZE) - 1, TZC_REGION_S_NONE,	\
 		PLAT_ARM_TZC_NS_DEV_ACCESS}
 
 #else