ARM: dts: rockchip: Sonoff-iHost: adjust SDIO for stability

Reduce max-frequency from 50MHz to 25MHz to improve WiFi module stability
on some Sonoff iHost units. Remove unsupported or redundant properties,
and keep only minimal, validated configuration.

Signed-off-by: Hao Zhang <hao.zhang@coolkit.cn>
Link: https://lore.kernel.org/r/20250509101419.460473-2-hao.zhang@coolkit.cn
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: ZHozz

arch/arm/boot/dts/rockchip/rv1126-sonoff-ihost.dtsi

@@ -342,16 +342,14 @@
 
 &sdio {
 	bus-width = <4>;
-	cap-sd-highspeed;
 	cap-sdio-irq;
 	keep-power-in-suspend;
-	max-frequency = <50000000>;
+	max-frequency = <25000000>;
 	mmc-pwrseq = <&sdio_pwrseq>;
 	non-removable;
 	pinctrl-names = "default";
 	pinctrl-0 = <&sdmmc1_clk &sdmmc1_cmd &sdmmc1_bus4>;
 	rockchip,default-sample-phase = <90>;
-	sd-uhs-sdr50;
 	vmmc-supply = <&vcc3v3_sd>;
 	vqmmc-supply = <&vcc_1v8>;
 	status = "okay";