usb: dwc3: Update PRTCAPDIR with GCTL register

Currently PRTCAPDIR with GCTL register is set as OTG mode.
Hence USB host mode functionality doesn't work. Fix this
issue by explicitly setting PRTCAPDIR as host or device
while starting USB host or device mode functionality.

Change-Id: Ie55a504ccc1562a7c071942d8a7b008419d975c3
Signed-off-by: Mayank Rana <mrana@codeaurora.org>