[media] m5mols: Remove superfluous irq field from the platform data struct

There is no need to put the IRQ number in driver's private platform
data structure as this can also be passed in struct i2c_lient.irq.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>