Verify Kconfigs symbols are not zero for hex and int type symbols

For hex and int type kconfig symbols, IS_ENABLED() doesn't work. Instead
check to make sure they're defined and not zero.  In some cases, zero
might be a valid value, but it didn't look like zero was valid in these
cases.

Change-Id: Ib51fb31b3babffbf25ed3ae4ed11a2dc9a4be709
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: http://review.coreboot.org/10886
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/southbridge/amd/agesa/hudson/acpi/fch.asl

@@ -179,12 +179,10 @@ Method(_INI, 0) {
 	/* Determine the OS we're running on */
 	OSFL()
 
-#ifdef CONFIG_HUDSON_IMC_FWM
-#if CONFIG_HUDSON_IMC_FWM
+#if defined(CONFIG_HUDSON_IMC_FWM) && CONFIG_HUDSON_IMC_FWM
 	#include "acpi/AmdImc.asl" /* Hudson IMC function */
 	ITZE() /* enable IMC Fan Control*/
 #endif
-#endif
 } /* End Method(_SB._INI) */
 
 Method(OSFL, 0){