coreinfo: Use IS_ENABLED() to query Kconfig variables

This will make the code work with the different styles
of Kconfig (emit unset bools vs don't emit unset bools)

Roughly, the patch does this, and a little bit of fixing up:

perl -pi -e 's,ifdef (CONFIG_.+?)\b,if IS_ENABLED\($1\),g' `find . -name *.[ch]`
perl -pi -e 's,ifndef (CONFIG_.+?)\b,if !IS_ENABLED\($1\),g' `find . -name *.[ch]`

Change-Id: Ia461a33541f58ff39e984119c44ece7e6c05608a
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: http://review.coreboot.org/10713
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

payloads/coreinfo/coreboot_module.c

@@ -20,7 +20,7 @@
 #include "coreinfo.h"
 #include <coreboot_tables.h>
 
-#ifdef CONFIG_MODULE_COREBOOT
+#if IS_ENABLED(CONFIG_MODULE_COREBOOT)
 
 #define MAX_MEMORY_COUNT 5