Change #ifdef and #if defined CONFIG_ bools to #if IS_ENABLED()

Kconfigs symbols of type bool are always defined, and can be tested with
the IS_ENABLED() macro.

symbol type except string.

Change-Id: Ic4ba79f519ee2a53d39c10859bbfa9c32015b19d
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: http://review.coreboot.org/10885
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/lib/rmodule.ld

@@ -30,7 +30,7 @@ SECTIONS
 		/* C read-only data. */
 		. = ALIGN(16);
 
-#ifdef CONFIG_COVERAGE
+#if IS_ENABLED(CONFIG_COVERAGE)
 		__CTOR_LIST__ = .;
 		*(.ctors);
 		LONG(0);