Revert "mm-video:vidc: Add the handling of MPEG-2 extension and user data."

This reverts commit 76c7c96da722bd62c125a144eed0ec26e5985966.

Reason: breaks build (VDEC_EXTRADATA_EXT_DATA and
VDEC_EXTRADATA_EXT_DATA not present in kernel headers)

Change-Id: I52e6fb447dc5a4893de36784049d5063245ff24d