libcamera: ipa: Add Soft IPA

Define the Soft IPA main and event interfaces, add the Soft IPA
implementation.

The current src/ipa/meson.build assumes the IPA name to match the
pipeline name. For this reason "-Dipas=simple" is used for the
Soft IPA module.

Auto exposure/gain and AWB implementation by Dennis, Toon and Martti.

Auto exposure/gain targets a Mean Sample Value of 2.5 following
the MSV calculation algorithm from:
https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf

Use CameraSensorHelper to convert the analogue gain code read from the
camera sensor into real analogue gain value. In the future this makes
it possible to use faster AE/AGC algorithm. Right now the CameraSensorHelper
lets us use the full range of analogue gain values.

If there is no CameraSensorHelper for the camera sensor in use, a
warning log message is printed.

Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> # sc8280xp Lenovo x13s
Tested-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Co-developed-by: Dennis Bonke <admin@dennisbonke.com>
Signed-off-by: Dennis Bonke <admin@dennisbonke.com>
Co-developed-by: Marttico <g.martti@gmail.com>
Signed-off-by: Marttico <g.martti@gmail.com>
Co-developed-by: Toon Langendam <t.langendam@gmail.com>
Signed-off-by: Toon Langendam <t.langendam@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

meson_options.txt

@@ -27,7 +27,7 @@ option('gstreamer',
 
 option('ipas',
         type : 'array',
-        choices : ['ipu3', 'rkisp1', 'rpi/vc4', 'vimc'],
+        choices : ['ipu3', 'rkisp1', 'rpi/vc4', 'simple', 'vimc'],
         description : 'Select which IPA modules to build')
 
 option('lc-compliance',