USB: at91 udc, support at91sam926x addresses

This is an update to the AT91 USB Device (Gadget) driver.

The base I/O address provided in the platform_device resources is now
ioremap()'ed instead of using a statically mapped memory area.  This
helps portability to the newer AT91sam926x processors.

The major change is that we now have to pass a 'struct at91_udc'
parameter to at91_udp_read() and at91_udp_write().

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>