mb/google/skywalker: Reset xsphy0 in mainboard_init

USB port 0 (P0) is force_suspended during the BootROM stage, and this
state won't be cleared in subsequent stages, causing P0 to become
unusable. Adding the P0 controller in coreboot ensures that the
force_suspended state is cleared, restoring P0 functionality.

BUG=b:417079837
BRANCH=None
TEST=Build passes and insert a USB device into USB port 0 can enumerate
     the USB device.

Signed-off-by: Liu Liu <ot_liu.liu@mediatek.corp-partner.google.com>
Change-Id: Ibe8649297d3236a8896d1045cdf23cb4b1313e43
Reviewed-on: https://review.coreboot.org/c/coreboot/+/87978
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yidi Lin <yidilin@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>

src/mainboard/google/skywalker/mainboard.c

@@ -91,6 +91,7 @@ static void mainboard_init(struct device *dev)
 
 	dpm_init();
 	setup_usb_host();
+	setup_usb_secondary_host();
 	spm_init();
 	power_on_fpmcu();
 	configure_audio();