coreboot: Replace all IS_ENABLED(CONFIG_XXX) with CONFIG(XXX)

This patch is a raw application of

 find src/ -type f | xargs sed -i -e 's/IS_ENABLED\s*(CONFIG_/CONFIG(/g'

Change-Id: I6262d6d5c23cabe23c242b4f38d446b74fe16b88
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31774
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/include/stddef.h

@@ -36,7 +36,7 @@ typedef unsigned int wint_t;
 #endif
 
 /* Work around non-writable data segment in execute-in-place romstage on x86. */
-#if defined(__PRE_RAM__) && IS_ENABLED(CONFIG_ARCH_X86)
+#if defined(__PRE_RAM__) && CONFIG(ARCH_X86)
 #define MAYBE_STATIC
 #else
 #define MAYBE_STATIC static