arm: socfpga: Fix typos in DT files (environmnet -> environment)

Fix a small typo in some of the SoCFPGA dts files that has spread via
copy-and-paste.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Chin Liang See <clsee@altera.com>

arch/arm/dts/socfpga_arria5_socdk.dts

@@ -21,7 +21,7 @@
 	};
 
 	aliases {
-		/* this allow the ethaddr uboot environmnet variable contents
+		/* this allow the ethaddr uboot environment variable contents
 		 * to be added to the gmac1 device tree blob.
 		 */
 		ethernet0 = &gmac1;

arch/arm/dts/socfpga_cyclone5_socdk.dts

@@ -21,7 +21,7 @@
 	};
 
 	aliases {
-		/* this allow the ethaddr uboot environmnet variable contents
+		/* this allow the ethaddr uboot environment variable contents
 		 * to be added to the gmac1 device tree blob.
 		 */
 		ethernet0 = &gmac1;

arch/arm/dts/socfpga_cyclone5_sr1500.dts

@@ -16,7 +16,7 @@
 
 	aliases {
 		/*
-		 * This allows the ethaddr uboot environmnet variable
+		 * This allows the ethaddr uboot environment variable
 		 * contents to be added to the gmac1 device tree blob.
 		 */
 		ethernet0 = &gmac1;