USB: gadget: Add OTG support for ci13xxx_udc

Add support for processing OTG feature requests like b_hnp_enable,
a_hnp_support, test mode features like otg_srp_reqd, otg_hnp_reqd and
HNP polling.

Change-Id: Icb2a8c32c3b566638e48d89bac1aeef453d0e8fa
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>