arm64: dts: rockchip: remove abused keep-power-in-suspend

keep-power-in-suspend was invented for SDIO only, so it should
not be used for eMMC node.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3368-px5-evb.dts

@@ -86,7 +86,6 @@ &emmc {
 	cap-mmc-highspeed;
 	clock-frequency = <150000000>;
 	disable-wp;
-	keep-power-in-suspend;
 	mmc-hs200-1_8v;
 	no-sdio;
 	no-sd;

arch/arm64/boot/dts/rockchip/rk3399-firefly.dts

@@ -632,7 +632,6 @@ &saradc {
 
 &sdhci {
 	bus-width = <8>;
-	keep-power-in-suspend;
 	mmc-hs400-1_8v;
 	mmc-hs400-enhanced-strobe;
 	non-removable;