arm64: dts: qcom: sm8250: camss: Add downstream camera pin defintions

There are a number of pin mux descriptions for the CAMSS block which are
defined downstream.

Bring in the definitions now. Subsequent changes will optionally activate
those muxes for different sm8250 based boards.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>