[ARM] 4145/2: AT91: Add support for AT91SAM9263 processor

Add support for the Atmel AT91SAM9263 processor.  It is similar to the
AT91SAM9260 but with more integrated peripherals, 5 GPIO banks, etc.

Original patch from Nicolas Ferre.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>