Remove useless extern gnvs declaration in smi handlers.

Change-Id: I3047badea8d4f61155f4e4f7d3d078426948162a
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/10228
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/mainboard/packardbell/ms2290/smihandler.c

@@ -31,11 +31,6 @@
 #include <pc80/mc146818rtc.h>
 #include <delay.h>
 
-/* The southbridge SMI handler checks whether gnvs has a
- * valid pointer before calling the trap handler
- */
-extern global_nvs_t *gnvs;
-
 static void mainboard_smm_init(void)
 {
 	printk(BIOS_DEBUG, "initializing SMI\n");