msm: ssm: Update the header structures

The long variable under 64-bit migration needs to be changed to
uint32_t. Also as the smd channel is fixed for communication,
SSM driver doesn't need to depend on device tree to read the
details.

Change-Id: I43cafef1260f53660c18298f4e7314c753cf3944
Signed-off-by: Katish Paran <kparan@codeaurora.org>