mb/tgl: Enable SaGv for TGL-UP3 RVP

BUG=none
BRANCH=none
TEST=Build and boot TGL-UP3 RVP with QS silicon successfully.

Change-Id: I5b84457a1455edfe500ce80ba7f7ca6ccce43666
Signed-off-by: Shreesh Chhabbi <shreesh.chhabbi@intel.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43276
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>
Reviewed-by: Wonkyu Kim <wonkyu.kim@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/intel/tglrvp/variants/tglrvp_up3/devicetree.cb b/src/mainboard/intel/tglrvp/variants/tglrvp_up3/devicetree.cb
index 5d4d246..2dd65c4 100644
--- a/src/mainboard/intel/tglrvp/variants/tglrvp_up3/devicetree.cb
+++ b/src/mainboard/intel/tglrvp/variants/tglrvp_up3/devicetree.cb
@@ -13,7 +13,7 @@
 	register "pmc_gpe0_dw2" = "GPP_E"
 
 	# FSP configuration
-	register "SaGv" = "SaGv_Disabled"
+	register "SaGv" = "SaGv_Enabled"
 	register "SmbusEnable" = "1"
 
 	register "usb2_ports[0]" = "USB2_PORT_MID(OC0)"		# Type-C Port1