mb/google/brya/vell: Add PS1/PS2 cutoff point

According intel Doc#634254 and Doc#608715
PS2/PS1 cross point = 5
PS1/PS0 cross point = 10
PS2 cutoff = 1.4*(PS2/PS1 cross point) = 7

1.3 is better magnification, it obtain by test
PS1 cutoff = 1.3*(PS1/PS0 cross point) = 13

BUG=b:241850120
BRANCH=brya
TEST='FW_NAME=vell emerge-brya coreboot'

Change-Id: I83e9682004e2c3644ad4a5565e6ab85be48ba22f
Signed-off-by: Shon Wang <shon.wang@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67394
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com>

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

@@ -547,4 +547,12 @@ chip soc/intel/alderlake
 			end
 		end
 	end
+
+	# VR Settings
+	register "domain_vr_config[VR_DOMAIN_IA]" = "{
+		.vr_config_enable = 1,
+		.psi1threshold = VR_CFG_AMP(13),
+		.psi2threshold = VR_CFG_AMP(7),
+	}"
+
 end