[media] V4L: Add camera ISO sensitivity controls

Add ISO sensitivity and ISO auto/manual controls. The sensitivity
values are related to level of amplification of the analog signal
between image sensor and ADC. These controls allow to support sensors
exposing an interface to accept the ISO values directly.

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>