[ARM] 4143/1: AT91: Prepare for AT91SAM9263 support

The Atmel AT91SAM9263 processor includes many more integrated
peripherals than Atmel's previous ARM9-based AT91 processors, so this
has necessitated a few changes to the core AT91 support.

These changes are:
      * The system peripheral I/O region we remap has increased from
        0xFFFA0000..0xFFFFFFFF to 0xFFF78000..0xFFFFFFFF.
      * The increased I/O region forces changes to entry-macro.S and
        debug-macro.S due to ARM's limited immediate offset addressing
        modes.
      * Maximum number of GPIO banks increases to 5.
      * 2 MMC controllers so the board-setup code needs to specify which
        controller it wishes to use when calling at91_add_device_mmc().

Original patch from Nicolas Ferre.

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