ARM: dts: socfpga: Add i2c alias to A10 SoCDK

The A10 SoCDK is missing the I2C bus alias, so DM I2C cannot assign
the I2C bus a bus number. Add the missing alias.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Chin Liang See <chin.liang.see@intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>

arch/arm/dts/socfpga_arria10_socdk.dtsi

@@ -23,6 +23,7 @@
 	aliases {
 		ethernet0 = &gmac0;
 		serial0 = &uart1;
+		i2c0 = &i2c1;
 	};
 
 	chosen {