leds: pwm-multicolor: Add check for fwnode_property_read_u32

Add a check to the return value of fwnode_property_read_u32()
in case it fails.

Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
Link: https://lore.kernel.org/r/20250223121459.2889484-1-ruc_gongyuanjun@163.com


Signed-off-by: Lee Jones <lee@kernel.org>