mb/google/nissa/var/glassway: Add convertible and clamshell WIFI SAR FW_CONFIG ids

Based on Gallida360 design, we add two new options for WIFI_SAR_ID:
- WIFI_SAR_ID_INTEL_CONVERTIBLE  2
- WIFI_SAR_ID_INTEL_CLAMSHELL    3

BUG=b:372354703
BRANCH=firmware-nissa-15217.B
TEST=emerge-nissa coreboot chromeos-bootimage

Change-Id: I1b58c4f572d4dbcb269d38485664ddc51e378e5e
Signed-off-by: Daniel Peng <Daniel_Peng@pegatron.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84779
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Eric Lai <ericllai@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jayvik Desai <jayvik@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/mainboard/google/brya/variants/glassway/overridetree.cb

@@ -20,6 +20,8 @@ fw_config
 	field WIFI_SAR_ID 10 12
 		option WIFI_SAR_ID_0		 0
 		option WIFI_SAR_ID_1		 1
+		option WIFI_SAR_ID_INTEL_CONVERTIBLE		 2
+		option WIFI_SAR_ID_INTEL_CLAMSHELL		 3
 	end
 	field STYLUS 14
 		option STYLUS_ABSENT		0