mmc: Atmel host kconfig cleanup for everyone else

This prevents those without an Atmel chip having a line in kernel
configuration which says "Atmel SD/MMC Driver" without any option.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/host/Kconfig

@@ -189,6 +189,7 @@ config MMC_AU1X
 
 choice
 	prompt "Atmel SD/MMC Driver"
+	depends on AVR32 || ARCH_AT91
 	default MMC_ATMELMCI if AVR32
 	help
 	  Choose which driver to use for the Atmel MCI Silicon