Revert "msm: vidc: Force the encoding driver to use PMEM."

This reverts commit bb17d9e508324295a11aad9c1bfa7df406d5f206.
vidc: allow for pmem to be used while the device is encoding

 * based off paul's commit, just a simpler way of handling it.

Change-Id: Ib33fdee22762811094933a6f9116152afc9afd89