ARM: dts: meson8b-odroidc1: add microSD support

The Odroid C1 features a microSD slot. This patch adds the necessary
DT bindings to support it.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm/boot/dts/meson8b.dtsi

@@ -206,6 +206,14 @@
 				function = "ethernet";
 			};
 		};
+
+		sd_b_pins: sd-b {
+			mux {
+				groups = "sd_d0_b", "sd_d1_b", "sd_d2_b",
+					"sd_d3_b", "sd_clk_b", "sd_cmd_b";
+				function = "sd_b";
+			};
+		};
 	};
 };