msm: vidc: Remove unnecessary check condition

Remove below check conditions which are not required
- userptr null check in dqbuf as it is valid to have null
  in some scenarios
- fps check which is skipping initial fps setting to firmware
- core validity check as it is not required to print debugq logs

CRs-Fixed: 2036629
Change-Id: I70484a21def5c115d458b19373b0aba359f4712f
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>