UPSTREAM: usb: dwc2: do not override forced dr_mode in gadget setup

UPSTREAM: usb: dwc2: do not override forced dr_mode in gadget setup

The host/device mode set with dr_mode should be kept all the time,
not being changed to OTG in gadget setup (by overriding CFGUSB_FORCEDEVMODE
and CFGUSB_FORCEHOSTMODE bits).

Change-Id: I80037fb325d00cb302c223a65ef3ac628955fe08
Acked-by: John Youn <johnyoun@synopsys.com>
Tested-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Przemek Rudy <prudy1@o2.pl>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
(cherry picked from commit ecd9a7ad453c5effc9a26355b79ee83f1337cba4)