ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT

There's no card detection for the eMMC, so this patch adds the missing
broken-cd property. This patch also sets bus width as 8 to add
MMC_CAP_8_BIT_DATA in the Host capabilities.

Cc: stable@vger.kernel.org # 3.16+
Fixes: 3047086d ("ARM: dts: berlin: enable SD card reader and eMMC for the BG2Q DMP")
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>