leds: qpnp-wled: Add auto-calibration logic for WLED

The auto-calibration logic checks if the current WLED sink
configuration is valid. It iterates through each sink
and checks if it causes an OVP fault. Based on this
information it detects and enables the valid sink
configuration.

Define 'qcom,auto-calibration-enable' to enable
auto-calibration.

CRs-Fixed: 2011194
Change-Id: If5e31d98db3e5dcab188a9d420f8f0e33bf2c16f
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>