[media] m5mols: Improve the interrupt handling routines

The work struct based interrupt handling is not flexible enough
as the M-5MOLS control sequence involves I2C access sequences
before and after an interrupt is generated. A single waitqueue is
enough for the job so remove the work struct based code.

Signed-off-by: HeungJun Kim <riverful.kim@samsung.com>
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>