usb: gadget: ci13xxx: initialize ep0{out,in} dynamically

Change ep0{out,in} macros into dynamically assigned pointers in
gadget initialization time.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>