[media] v4l2-ctrls: Add missing qmenu entries for MPEG ctrls

V4l2 control framework mandates a qmenu entry for each control item.
Validate_new() function accesses the qmenu entry for control item,
and any missing qmenu entries causes a crash within this function.
This patch fixes those crashes.

CRs-Fixed: 2196184
Change-Id: Ibbac1510df99e03356409392eb5f10bdc599e6c3
Signed-off-by: Chinmay Sawarkar <chinmays@codeaurora.org>