arm64: dts: rockchip: remove px30 emmc_pwren pinctrl

That gpio1-b0 can only be flash_cs apart from a regular gpio,
so there is no power-related pinmux for the emmc for this pin.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20190917082659.25549-3-heiko@sntech.de

arch/arm64/boot/dts/rockchip/px30.dtsi

@@ -1648,11 +1648,6 @@ emmc_cmd: emmc-cmd {
 					<1 RK_PB2 2 &pcfg_pull_up_8ma>;
 			};
 
-			emmc_pwren: emmc-pwren {
-				rockchip,pins =
-					<1 RK_PB0 2 &pcfg_pull_none>;
-			};
-
 			emmc_rstnout: emmc-rstnout {
 				rockchip,pins =
 					<1 RK_PB3 2 &pcfg_pull_none>;