src/soc/skylake: Fix Null pointer dereferences

Fix bug detected by coverity to handle the NULL pointer dereference

Coverity Issues:
* 1379849
* 1379848

TEST=Build and run on skylake platform

Change-Id: Iec7a88a03531bbfeb72cedab5ad93d3a4c23eef5
Signed-off-by: Shaunak Saha <shaunak.saha@intel.com>
Reviewed-on: https://review.coreboot.org/21909
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/skylake/pmutil.c

@@ -216,6 +216,7 @@ void soc_get_gpi_gpe_configs(uint8_t *dw0, uint8_t *dw1, uint8_t *dw2)
 	DEVTREE_CONST struct device *dev = dev_find_slot(0, PCH_DEVFN_PMC);
 	if (!dev || !dev->chip_info) {
 		printk(BIOS_ERR, "BUG! Could not find SOC devicetree config\n");
+		return;
 	}
 	config = dev->chip_info;