dt-bindings: leds: add TI/National Semiconductor LP5812 LED Driver

dt-bindings: leds: add TI/National Semiconductor LP5812 LED Driver

The LP5812 is a 4x3 RGB LED driver with an autonomous animation
engine and time-cross-multiplexing (TCM) support for up to 12 LEDs
or 4 RGB LEDs. It supports both analog (256 levels) and PWM (8-bit)
dimming, including exponential PWM for smooth brightness control.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Nam Tran <trannamatk@gmail.com>
Link: https://patch.msgid.link/20251221041950.4631-2-trannamatk@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>