board: sama5d2_xplained: remove unnecessary header files

Remove the unnecessary header files.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>

board/atmel/sama5d2_xplained/sama5d2_xplained.c

@@ -11,8 +11,6 @@
 #include <dm.h>
 #include <i2c.h>
 #include <lcd.h>
-#include <mmc.h>
-#include <spi.h>
 #include <version.h>
 #include <asm/io.h>
 #include <asm/arch/at91_common.h>