ARM: move udc_pxa2xx.h to linux/platform_data

Move the PXA2xx/IXP4xx UDC header file into linux/platform_data as it
only contains a driver platform data structure.

Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>