To enable the Simple Soft ISP and Soft IPA for simple pipeline handler
configure the build with:
  -Dpipelines=simple/simple -Dipas=simple/simple

If the pipeline uses Converter, Soft ISP and Soft IPA aren't
available.

Configuring the build with just:
  -Dpipelines=simple
makes it to work like before - Soft ISP and Soft IPA aren't used.

Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> # sc8280xp Lenovo x13s
Tested-by: Pavel Machek <pavel@ucw.cz>