[media] si4713: Modified i2c driver to handle cases where interrupts are not used

Checks have been introduced at several places in the code to test if an
interrupt is set or not. For devices which do not use the interrupt, to
get a valid response, within a specified timeout, the device is polled
instead.

Signed-off-by: Dinesh Ram <dinesh.ram@cern.ch>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Eduardo Valentin <edubezval@gmail.com>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>