media: dvb: Support indexing of recorded content

Indexing of recorded content is required by applications
in order to perform trick-modes on the recorded content.
The feature allows applications to specify different
kinds of indexing types and get notifications on the detected
index entries in the recorded content.

Change-Id: Idbda0c316fcc5d558e45a803e54e39f72aeecc9e
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>