ARM: dts: rockchip: Fix sdmmc_pwren's pinmux setting for RK3128

RK3128's reference design uses sdmmc_pwren pincontrol as GPIO - see [0].

Let's change it in the SoC DT as well.

[0] rockchip-linux/kernel@8c62deaf6025

Fixes: a0201bf ("ARM: dts: rockchip: add rk3128 soc dtsi")
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Link: https://lore.kernel.org/r/20231127184643.13314-2-knaerzche@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: knaerzche

arch/arm/boot/dts/rockchip/rk3128.dtsi

@@ -848,7 +848,7 @@
 			};
 
 			sdmmc_pwren: sdmmc-pwren {
-				rockchip,pins = <1 RK_PB6 1 &pcfg_pull_default>;
+				rockchip,pins = <1 RK_PB6 RK_FUNC_GPIO &pcfg_pull_default>;
 			};
 
 			sdmmc_bus4: sdmmc-bus4 {