ARM: DTS: am3517-evm-u-boot: Mark MMC1 with cd-inverted

In order to use the device tree for MMC, the card-detect pin
needs to be inverted.  This patch places this into the
am3517-evm-u-boot.dtsi file to keep the main DTS and DTSI files
clean and in-sync with Linux
Signed-off-by: NAdam Ford <aford173@gmail.com>

arch/arm/dts/am3517-evm-u-boot.dtsi

@@ -10,6 +10,10 @@
 	};
 };
 
+&mmc1 {
+	cd-inverted;
+};
+
 &uart1 {
 	reg-shift = <2>;
 };