media: atmel: atmel-isc-base: allow wb ctrls to be changed when isc is not configured

media: atmel: atmel-isc-base: allow wb ctrls to be changed when isc is not configured

When attempting to change the white balance (WB) ctrls before starting
streaming, e.g.:

 # v4l2-ctl -L

User Controls
..
            blue_component_gain 0x009819c1 (int)    : min=0 max=8191 step=1 default=512 value=512 flags=slider
..
 # v4l2-ctl --set-ctrl=blue_component_gain=500
 # v4l2-ctl -L
..
            blue_component_gain 0x009819c1 (int)    : min=0 max=8191 step=1 default=512 value=500 flags=slider
..

These will not be written to the internal data struct and will not be
written to the WB hardware module.
Thus, after starting streaming, they will be reset to default:

 # v4l2-ctl -L
..
            blue_component_gain 0x009819c1 (int)    : min=0 max=8191 step=1 default=512 value=512 flags=slider
..

It does not make much sense to not be able to configure the WB controls
at all times. Even if the sensor would not be RAW Bayer (and in this case the
WB module is unavailable), the user could configure the ISC itself, as the
ISC should not care about the sensor format.
Thus, when WB module is available (if the sensor changes format e.g.) it will
be already configured as be user's desires.
In consequence, remove the check in isc_s_awb_ctrl that will return if ISC
does not know the sensor format.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>