leds: pwm: Clear the led structure before parsing each child node

leds: pwm: Clear the led structure before parsing each child node

I defined 2 leds in the device tree, in the 1st led node, the
max-brightness is set to 248, while in the 2nd led node, I
mis-spelled the max-brightness to max-brighttness, but the driver
is still able to get the max-brightness 248 for the 2nd node,  that
is because the led structure is not cleared before parsing each child
node.

	pwmleds {
		compatible = "pwm-leds";

		pwm-green {
			...
			max-brightness = <248>;
		};

		pwm-red {
		        ...
			max-brighttness = <128>;
		};

Signed-off-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221220073335.393489-1-hui.wang@canonical.com