warp7: Remove unneeded headers after DM conversion

After DM conversion the I2C and MMC related board codes have been
removed, so remove the corresponding header files as well.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
diff --git a/board/warp7/warp7.c b/board/warp7/warp7.c
index 6ebeb08..49f290f 100644
--- a/board/warp7/warp7.c
+++ b/board/warp7/warp7.c
@@ -11,12 +11,8 @@
 #include <asm/gpio.h>
 #include <asm/mach-imx/hab.h>
 #include <asm/mach-imx/iomux-v3.h>
-#include <asm/mach-imx/mxc_i2c.h>
 #include <asm/io.h>
 #include <common.h>
-#include <fsl_esdhc.h>
-#include <i2c.h>
-#include <mmc.h>
 #include <asm/arch/crm_regs.h>
 #include <usb.h>
 #include <netdev.h>