ARM: dts: msm: Enable SDHC support for MSM8939

Enable SDHC slots - slot 1 used for eMMC and slot 2 used for
SD2.0/SD3.0/SDIO cards, on 8939 CDP, MTP, QRD platforms.

Change-Id: I4c7dfcf076c361c145be63cd06482027e24988bd
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>