mb/google/octopus/variants/casta: Disable xHCI compliance mode

Disable xHCI compliance mode to prevent SS hub detection issue.

BRANCH=firmware-octopus-11297.B
BUG=none
TEST=built

Change-Id: I7a9bbc92565e752a8f8f4689519c100594596701
Signed-off-by: Seunghwan Kim <sh_.kim@samsung.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44438
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/octopus/variants/casta/overridetree.cb

@@ -139,4 +139,7 @@ chip soc/intel/apollolake
 			end
 		end	# - I2C 6
 	end
+
+	# Disable compliance mode
+	register "DisableComplianceMode" = "1"
 end