Enhance USB 2.0 C0/C1 A0/A1 SI by increasing the level of
"HS DC Voltage Level" and " Disconnect Threshold Adjustment" registers.
COMPDISTUNE0: 0x3->0x7
TXVREFTUNE0: 0x6->0xf
BUG=b:166398726
BRANCH=zork
TEST=1. emerge-zork coreboot
2. check U2 register is set correctly.
3. U2 SI all pass
Change-Id: I69d942605c6d43ece0d71f67df3a5e00b998219b
Signed-off-by: Kevin Chiu <kevin.chiu@quantatw.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46545
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>