Ip sleep will auto exit if vbus comparison circuit of u2 phy is
disabled when system tries to enter suspend mode, so get vbus-valid
status from mac but not from u2 phy when enable DRD mode to fix
the issue.
Signed-off-by: NChunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>