arm64: dts: qcom: apq8016-sbc: Set ov5640 assigned-clock

arm64: dts: qcom: apq8016-sbc: Set ov5640 assigned-clock

The driver for the ov5640 doesn't do a set-rate, instead it expects the
clock to already be set at an appropriate rate.

Similarly the yaml for ov5640 doesn't understand clock-frequency. Convert
from clock-rate to assigned-clock and assigned-clock-rate to remediate.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230811234738.2859417-5-bryan.odonoghue@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>