msm: vidc: avoid setting smoothstreaming for Q6

Smoothstreaming is not a tested functionality on Q6.
This change will return error to all clients trying
to configure Q6 in smoothstreaming mode.

Change-Id: If520d136cd29b3b37759d0fb179538e31b9b71d9
Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>