In Cyclone 5 SoC platform, the first USB probing is failed but second
probing is success. DWC2 USB driver read gsnpsid register right after
de-assert reset, but controller is not ready yet and it returns gsnpsid 0.
Polling reset status after de-assert reset to solve the issue.
Retry with this fix more than 10 times without issue.
Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>