arm64: dts: meson: nanopi k2: add sd DDR50

Add UHS ddr50 mode to the nanopi k2
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Acked-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: NKevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-gxbb-nanopi-k2.dts

@@ -301,6 +301,7 @@
 	sd-uhs-sdr12;
 	sd-uhs-sdr25;
 	sd-uhs-sdr50;
+	sd-uhs-ddr50;
 	max-frequency = <100000000>;
 	disable-wp;