ARM: dts: Add SDHC1 and SDHC2 devices for MPQ8092

Add device tree entries to enable standard host controllers
for eMMC and SD devices.

Change-Id: I1ff9b091d9f7f655a148dfcfc6975314431a3366
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>