[media] v4l: omap4iss: Enable/disabling the ISP interrupts globally

ISP interrupts are enabled/disabled when starting/stopping the IPIPEIF
or resizer. This doesn't permit using the two modules in separate
pipelines. Fix it by enabling/disabling the ISP interrupts at the same
time as the ISS interrupts, in the ISS device get/put operations.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>