media: v4l2-ctrls: drop 'elems' argument from control type ops.

The type ops for equal, init and validate have an elems argument,
but this can be taken from struct v4l2_ctrl: ctrl->elems for
equal and init, and ctrl->new_elems for validate (since you are
validating a new control value).

So drop this argument and update all callers.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>