MdeModulePkg/UsbBus: reduce the port status polling before port reset

MdeModulePkg/UsbBus: reduce the port status polling before port reset

This change is used to remove the port status polling in port reset
functions.

Why it's needed is because:
1) The same polling on same port has taken place prior to this removed
one. See UsbEnumeratePort()->GetPortStatus(). So this polling in
UsbEnumerateNewDev()->ResetPort() is redundant.
2) EDKII Xhci driver hooks all GetPortStatus() operations. If we don't
remove this one, XHCI driver's XhcPollPortStatusChange() may enter twice
in reset process and wrongly think the device is unplugged.

Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>