ARM: DT: msm8660: Add sdcc nodes

Add the sdcc nodes to support the SD card controller using pl180
mmci driver. We also add a temporary fixed regulator until the
regulator driver is mainlined.

Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kumar Gala <galak@codeaurora.org>