Fixes:

drivers/usb/gadget/pxa27x_udc.c:1263:13: warning: 'pxa27x_change_interface' defined but not used [-Wunused-function]

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Fix following:
drivers/usb/gadget/pxa27x_udc.c:1482:1: warning: initialization from incompatible pointer type

Signed-off-by: Marek Belisko <marek.belisko@open-nandra.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

The timings of the poller calling have changed, digging out
a latent bug in pxa27x udc controller.
The polling routine is called before the probe function is
called, and the driver internal are not initialized at that
time. This triggers a NULL pointer exception.

Fix it by moving poller registration after driver probe.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Adapt mainline kernel pxa27x_udc driver to barebox :
 - remove function header comments as they are in mainline
 - test it with serial gadget

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>