dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control

Document the compatible for aspeed,ast2600-pwm-tach device, which can
support up to 16 PWM outputs and 16 fan tach input.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240221104025.1306227-3-billy_tsai@aspeedtech.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>