arch/*: Update Kconfig symbol usage

- Update all symbols to use IS_ENABLED()
- Update non-romcc usage to use 'if' instead of '#if' where it
makes sense.

Change-Id: I5a84414d2d1631e35ac91efb67a0d4c1f673bf85
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/20005
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/arch/arm/armv7/mmu.c

@@ -39,7 +39,7 @@
 #include <arch/cache.h>
 #include <arch/io.h>
 
-#if CONFIG_ARM_LPAE
+#if IS_ENABLED(CONFIG_ARM_LPAE)
 /* See B3.6.2 of ARMv7 Architecture Reference Manual */
 /* TODO: Utilize the contiguous hint flag */
 #define ATTR_BLOCK (\