media: iris: Split power on per variants

media: iris: Split power on per variants

Current devices use same power up sequence, but starting with Qualcomm
SM8750 (VPU v3.5) the sequence will grow quite a bit, so allow
customizing it.  No functional change so far for existing devices.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>