[media] m5mols: Fix cast warnings from m5mols_[set/get]_ctrl_mode

Fixes following warnings on 64-bit architectures:

m5mols.h: In function 'm5mols_set_ctrl_mode':
m5mols.h:326:15: warning: cast to pointer from integer of different
size [-Wint-to-pointer-cast]

m5mols.h: In function 'm5mols_get_ctrl_mode':
m5mols.h:331:9: warning: cast from pointer to integer of different
size [-Wpointer-to-int-cast]

drivers/media/i2c/m5mols/m5mols_controls.c:466:2: warning: cast
from pointer to integer of different size

Cc: 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>