ARM: dts: rockchip: enable HS200/DDR52 mode for emmc on rk3288-popmetal

Enable these two modes to speed up the booting and improve
the performance.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rk3288-popmetal.dts

@@ -147,6 +147,8 @@ &emmc {
 	bus-width = <8>;
 	cap-mmc-highspeed;
 	disable-wp;
+	mmc-ddr-1_8v;
+	mmc-hs200-1_8v;
 	non-removable;
 	num-slots = <1>;
 	pinctrl-names = "default";