AT91: atmel-mci: Platform configuration to the the atmel-mci driver

AT91: atmel-mci: Platform configuration to the the atmel-mci driver

Created a modified version of the at91sam9g20 evaluation kit platform
(board-sam9g20ek-2slot-mmc.c) and device support to make use of the
updated atmel-mci driver.

As the use of two slots modify GPIO pin allocation, we create another
board file.

This requires getting the most updated arch/arm/tools/mach-types from
http://www.arm.linux.org.uk/developer/machines/download.php to have the machine
type for the at91sam9g20ek-2slot-mmc board.

[nicolas.ferre@atmel.com: printk, slot_count modification in at91sam9260_devices.c file]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Rob Emanuele <rob@emanuele.us>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>