msm: vidc: remove adding of extra input buffers for encoder

When power save mode for 4K recording is enabled, driver adds two
extra input buffers to enable DCVS. This change removes the addition
of extra buffers as camera adds them now.

Change-Id: I6b7a789cd146f1441ceaeb2b3ede178e2be94d5f
Signed-off-by: Ashray Kulkarni <ashrayk@codeaurora.org>