arm64: dts: qcom: sc8280xp-x13s: enable camera privacy indicator

arm64: dts: qcom: sc8280xp-x13s: enable camera privacy indicator

Leverage newly introduced 'leds' and 'led-names' properties to pass
indicator's phandle and function to v4l2 subnode. The latter supports
privacy led since couple of years ago under 'privacy-led' designation.
Unlike initially proposed trigger-source based approach, this solution
cannot be easily bypassed from userspace, thus reducing privacy
concerns.

Signed-off-by: Aleksandrs Vinarskis <alex@vinarskis.com>
Tested-by: Steev Klimaszewski <threeway@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250910-leds-v5-4-bb90a0f897d5@vinarskis.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>