usb: gadget: composite: handle otg status selector request from OTG host

If gadget with HNP polling support receives GetStatus request of otg
status selector, it feedback to host with host request flag to indicate
if it wants to take host role.

Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>