mb/google/brya/variants/primus: config dram speed to 3733

This change config the DRAM speed to 3733 for primus.

BUG=b:200752480
BRANCH=none
TEST=Verified that `dmidecode -t17` shows the correct
     configured memory speed

Signed-off-by: Casper Chang <casper_chang@wistron.corp-partner.google.com>
Change-Id: I2f3a9489dddcf102b0ffc71eb9cdab6ad38d1391
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57867
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

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

@@ -24,6 +24,8 @@ end
 chip soc/intel/alderlake
 
 	register "SaGv" = "SaGv_Enabled"
+	register "MaxDramSpeed" = "3733"
+
 	# Intel Common SoC Config
 	#+-------------------+---------------------------+
 	#| Field             |  Value                    |