fbdev: msm: Use dynamic allocation for SID variable

The physical address of SID variable when passed to TZ during
SCM call for secure display was causing an out of range address
error from TZ followed by SMMU fault. The SID was defined
as a local stack variable. Use dynamic allocation for
SID variable to avoid this address out of range error.

Change-Id: Ia1a49ccdf2b386b6d600676ecf5a2d4a53b993b9
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>