Revert "usb: dwc3: gadget: use update transfer command"

This reverts commit 6bb4fe12
("usb: dwc3: gadget: use update transfer command"). If we get
a Xfer Not Ready event with reason "Transfer Active" issuing
update transfer for the endpoint for any pending request
results into transfer stall on the endpoint. Hence do not use
update transfer command for on-demad transfers.

Change-Id: Iec1c5913efe1dd266506f973951f22a2170fce77
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>