disp: msm: sde: ignore sspp check in rm splash init during vm handoff

The last commit in primary-vm before transitioning to
trusted-vm during trusted-ui usecase will be NULL
commit for video mode. In the current splash path,
rm reserve during cont splash res init will succeed
only if there are sspps staged on the mixer. Avoid
this check for vm handoff usecase.

Change-Id: I9829c66f8eb856cc009edc35e489bc9adad1c5d7
Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org>