Use a switch() on this function, just like on other ioctl
handlers and handle parameters inside each part of the
switch.

That makes it easier to integrate with the already existing
ioctl handler function.
Reviewed-by: NShuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>