PWM0 on rk3588-tiger is connected to the BLT_CTRL pin of the Q7 connector
meant as the name implies to control a backlight device.

Therefore set the correct M1 pinctrl variant for it. The M0 variant
cannot ever be used because that pin is routed to a connector pin on the
Q7 connector that is reserved for CAN use and the pin reachable by the M2
variant is reserved for the embedded MCU on the SoM.

Fixes: 6173ef24 ("arm64: dts: rockchip: add RK3588-Q7 (Tiger) SoM")
Signed-off-by: Heiko Stuebner <heiko.stuebner@cherry.de>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Link: https://lore.kernel.org/r/20240603192254.2441025-1-heiko@sntech.deSigned-off-by: Heiko Stuebner <heiko@sntech.de>