msm: vidc: remove volatile flag for controls

Volatile controls support is not required and hence
remove it. Remove menu_skip_mask initialization for
v4l2 standard non menu type controls as they need
step value initialization (step and menu_skip_mask
are union for standard controls).

Change-Id: I415219fcac8fce3e34a293b1348f13f70271218b
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>