msm_fb: hdmi: hdmi 3d length check

This change fixes a case where the length of 3d data is not
properly used which could have resulted in wrong 3d data parsing.

CRs-Fixed: 445505
Change-Id: Id285204bdb8c2d881becaa5b07b973eba4240d93
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>