V4L/DVB: v4l2-ctrls: Whitespace cleanups

Fixes 37 checkpatch.pl warnings like:

WARNING: please, no space before tabs
+^Icase V4L2_CID_MPEG_VIDEO_PULLDOWN: ^Ireturn "Video Pulldown";$

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>