arm64: dts: qcom: apq8016-sbc: Rename ov5640 enable-gpios to powerdown-gpios

arm64: dts: qcom: apq8016-sbc: Rename ov5640 enable-gpios to powerdown-gpios

There are two control lines controlled by GPIO going into ov5640

- Reset
- Powerdown

The driver and yaml expect "reset-gpios" and "powerdown-gpios" there has
never been an "enable-gpios".

Fixes: 39e0ce6cd1bf ("arm64: dts: qcom: apq8016-sbc: Add CCI/Sensor nodes")
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230811234738.2859417-6-bryan.odonoghue@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>