mmc: atmel-mci: remove include <mach/cpu.h>

Header file not needed anymore as we have removed the calls to
cpu_is_xxx() macro.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Chris Ball <cjb@laptop.org>