mm-video: Revert dynamic buffer changes

 * These changes trigger a race condition at EOS on the current
   version of Venus. Revert for now.

Revert "mm-video-v4l2: vidc: vdec: implement buffer req for Adaptive SS"

This reverts commit f61aaa2a1b79cc0755fe5dd73b8c79be7137aef1.

Revert "mm-video: vidc: Set the output buffer size properly"

This reverts commit e0676b4954d0b6517d2ed8cbf7483651bc47591b.

Revert "mm-video: vidc: Restore sanity representing buffer sizes in dyn buf mode"

This reverts commit 45d18017bf32d1de4ce3a7327c99330a96ada24c.

Change-Id: I6b06714e5574e9cf4e219c6de5e68e83d0662ac6
(cherry picked from commit 6628e2530f0fe643520efaa591e6883116278898)