We have a very convoluted if/else legacy here which needs to be
rationalised to make it more sustainable.

Adding in another Soc or two will make some of these if statements into
increasingly large multi-clause behemoths.

Introduce switches in the obvious places to despaghetiify.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>