src: Drop unused include <timestamp.h>

Change-Id: I7e181111cd1b837382929071a350b94c3afc1aaa
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31784
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>

src/soc/intel/skylake/romstage/romstage.c

@@ -37,7 +37,6 @@
 #include <stage_cache.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <timestamp.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 
 /* SOC initialization before RAM is enabled */