msm: camera: fix memory leak in actuator

actuator init table is not deallocated while camera is closed
This change hooks up power down call in mctl release

Change-Id: Ia5516da76dc9534bbdb9555ccd65316e20ef5c14
Signed-off-by: Sreesudhan Ramakrish Ramkumar <srramku@codeaurora.org>