ADV7604_FMT_CHANGE events was debounced in adv7604_isr() to avoid
that a receiver with a unstable input signal would block the event
handling for other inputs. This solution was prone to errors.

A better protection agains interrupt blocking is to delay the call
of the interrupt service routine in the adv7604 driver if too many
interrupts are received within a given time.
Signed-off-by: NMats Randgaard <matrandg@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>