src/soc: Add missing 'include <types.h>'

<types.h> is supposed to provide <stdint.h> and <stddef.h>.
When <types.h> is included, <stdint.h> and/or <stddef.h> is removed.

Change-Id: I2db0a647bc657a3626cb5e78f23e9198e290261a
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32810
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>

src/soc/intel/skylake/graphics.c

@@ -25,6 +25,7 @@
 #include <drivers/intel/gma/opregion.h>
 #include <soc/nvs.h>
 #include <soc/ramstage.h>
+#include <types.h>
 
 uintptr_t fsp_soc_get_igd_bar(void)
 {