mb/google/brya/variants/primus: Enable SaGv support

This patch enables SaGv support for primus.

BUG=b:196286180

Signed-off-by: Ariel Fang <ariel_fang@wistron.corp-partner.google.com>
Change-Id: I00074e348dd6347602c18dcfd231a890153b4685
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57135
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

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

@@ -23,6 +23,7 @@ end
 
 chip soc/intel/alderlake
 
+	register "SaGv" = "SaGv_Enabled"
 	# Intel Common SoC Config
 	#+-------------------+---------------------------+
 	#| Field             |  Value                    |