[media] omap3isp: ccdc: Don't timeout on stream off when the CCDC is stopped

When the CCDC is already stopped due to a buffer underrun, the stop
state machine won't advance in BT.656 mode as no interrupt are generated
by the stopped CCDC in that mode. Handle this case explicitly in the
ccdc_disable() function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Enrico Butera <ebutera@users.sourceforge.net>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>