The driver is usable on the newer SAM9 processors so replace all text
references to AT91RM9200 with just AT91.

The controller bug where all the words are byte-swapped is fixed on the
AT91SAM9 processors.  The byte-swapping work-around therefore only needs
to be done if cpu_is_at91rm9200().
[Original patch from Wojtek Kaniewski]

The AT91RM9200 and AT91SAM9260 processors support two MMC/SD slots - the
slot which is connected is now passed via the platform_data and the
correct slot selected in the AT91_MCI_SDCR register.

The driver should not be calling at91_set_gpio_output() since the VCC
pin should have already been configured as an output in the
processor/board setup code.  The driver should call
at91_set_gpio_value().
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>