arm64: dts: mediatek: mt7986: drop "#clock-cells" from PWM

[ Upstream commit 0b721691f0c80af682d0ef3aa4a177c23d41b072 ]

PWM is not a clock provider and its binding doesn't specify
"#clock-cells" property.

This fixes:
arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dtb: pwm@10048000: '#clock-cells' does not match any of the regexes: 'pinctrl-[0-9]+'
        from schema $id: http://devicetree.org/schemas/pwm/mediatek,mt2712-pwm.yaml#

Fixes: eabb04d ("arm64: dts: mt7986: add PWM")
Cc: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20240101182040.28538-1-zajec5@gmail.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

arch/arm64/boot/dts/mediatek/mt7986a.dtsi

@@ -242,7 +242,6 @@
 		pwm: pwm@10048000 {
 			compatible = "mediatek,mt7986-pwm";
 			reg = <0 0x10048000 0 0x1000>;
-			#clock-cells = <1>;
 			#pwm-cells = <2>;
 			interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&topckgen CLK_TOP_PWM_SEL>,