Revert "[media] media: Init the reserved fields of struct media_link_desc"

Reverting this commit to pull in the upstream version of this fix.
It'll make future kernel migrations easier.

This reverts commit e28d0509.

Change-Id: Iab08f6c239cde9d59ed025cb68cbf233b777a614
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>