arm: Rework usage of CONFIG_ARMV[78]_SECURE_BASE in linker scripts

In order to avoid defining CONFIG_ARMV[78_]SECURE_BASE as empty in the
linker scripts, if not already defined, add and use
__ARMV[78_]SECURE_BASE for when the base is not defined and we want the
linker scripts to continue.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/cpu/armv8/u-boot.lds b/arch/arm/cpu/armv8/u-boot.lds
index 8fe4682..fb6a30c 100644
--- a/arch/arm/cpu/armv8/u-boot.lds
+++ b/arch/arm/cpu/armv8/u-boot.lds
@@ -51,10 +51,12 @@
 	}
 
 #ifndef CONFIG_ARMV8_SECURE_BASE
-#define CONFIG_ARMV8_SECURE_BASE
+#define __ARMV8_SECURE_BASE
 #define __ARMV8_PSCI_STACK_IN_RAM
+#else
+#define __ARMV8_SECURE_BASE	CONFIG_ARMV8_SECURE_BASE
 #endif
-	.secure_text CONFIG_ARMV8_SECURE_BASE :
+	.secure_text __ARMV8_SECURE_BASE :
 		AT(ADDR(.__secure_start) + SIZEOF(.__secure_start))
 	{
 		*(._secure.text)