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

Since the first LFPS timeout causes xHCI to enter compliance
mode, the SS hub cannot be enumerated. The resolution is to
disable xHCI compliance mode.

BRANCH=octopus
BUG=b:149723583
TEST=Verified USB operation successfully.

Signed-off-by: tong.lin <tong.lin@bitland.corp-partner.google.com>
Change-Id: I3e6ab6ec0c4865cf2467da900f13d18468ff356f
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39968
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Marco Chen <marcochen@google.com>
diff --git a/src/mainboard/google/octopus/variants/phaser/overridetree.cb b/src/mainboard/google/octopus/variants/phaser/overridetree.cb
index 625c2a6..b80d031 100644
--- a/src/mainboard/google/octopus/variants/phaser/overridetree.cb
+++ b/src/mainboard/google/octopus/variants/phaser/overridetree.cb
@@ -173,4 +173,7 @@
                        end
 		end	# - I2C 7
 	end
+
+	# Disable xHCI compliance mode
+	register "DisableComplianceMode" = "1"
 end