intel/wifi: Add WGDS ACPI method for Geo Aware SAR

To comply with all relevant bodies throughout the world, SAR settings
take into account the lowest common denominator Tx power settings. This
setup may lead to non-optimal performance when the user location is in a
country that may allow higher power setting. The purpose of Wireless Geo
Delta Settings (WGDS) is to provide offset settings for FCC, Europe,
Japan and Rest of the world. These offsets would be added (by Intel wifi
driver) to the base SAR Tx Power as defined in WRDS and EWRD

BUG=b:65155728
BRANCH=none
TEST=WGDS ACPI table gets created as expected.

Change-Id: I4f602e3f95ff3545db6cc6e428beb9a36abd9296
Signed-off-by: Pratik Prajapati <pratikkumar.v.prajapati@intel.com>
Reviewed-on: https://review.coreboot.org/21098
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/drivers/intel/wifi/chip.h

@@ -28,6 +28,9 @@
 /* EWRD Domain type */
 #define EWRD_DOMAIN_TYPE_WIFI 0x7
 
+/* WGDS Domain type */
+#define WGDS_DOMAIN_TYPE_WIFI 0x7
+
 struct drivers_intel_wifi_config {
 	unsigned wake; /* Wake pin for ACPI _PRW */
 };