soc/intel/common: Add prototype for global_reset() reset

Add prototype for global_reset() that some SoCs need to provide.

BUG=chrome-os-partner:54149
BRANCH=none
TEST=none

Change-Id: I8afe076b6f4f675b3c6a3ec0e4dd69f950baa4ef
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/15333
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/reset.h

@@ -8,5 +8,7 @@ void hard_reset(void);
 #endif
 void soft_reset(void);
 void cpu_reset(void);
+/* Some Intel SoCs use a special reset that is specific to SoC */
+void global_reset(void);
 
 #endif