ARM: dts: msm: Restore sdcc registers on sdxpoorwills

SDCC registers on sdxpoortwills won't be retained upon CX
power collapse. Adding restore dt flag so that needed SDCC registers
would be saved before CX power collapse and restored while resuming.

Change-Id: Ib6e67c4ffa8ad64c1970e318f4e14f482d154820
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>