usb: qdss: Don't STARTXFER with usb_ep_enable() with USB BAM endpoint

USB BAM related endpoint's TRB ring is configured with platform specific
usb_ep_queue() API which also does STARTXFER with CMDIOC set. Current
code performs STARTXFER (without CMDIOC set) with usb_ep_enable() which
results into performing 2 times STARTXFER with USB BAM endpoint. Fix
this issue by endless flag with USB BAM endpoint and avoiding STARTXFER
with usb_ep_enable() for USB BAM endpoint.

Change-Id: Ifad1c9b3dd63c46d590f0552c452f238fde76161
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>