usb: gadget: Move udc_priv bit fields to MSM central header file.

The req->udc_priv value is used to transfer parameters from a function
driver to a udc, for enabling sps/bam mode for MSM architecture.

This change moves the definitions of the bit fields inside the udc_priv to
msm_hsusb.h in order to avoid duplicate definitions in u_bam.c and
ci13xxx_udc.h. Also this will allow other function drivers and other udcs
to use this definitions, for example, debug class over dwc3 udc.

Change-Id: I37a011524f7ba6d06029d1f3ab3f58d4cb248e4d
Signed-off-by: Ido Shayevitz <idos@codeaurora.org>