arm64: dts: ls208xa: Change I2C clock name to ipg to fix DTB_CHECK warning

dt_binding require I2C's clock name is "ipg". Change it to "ipg" from "i2c"
to fix below DTB_CHECK warning.
arch/arm64/boot/dts/freescale/fsl-ls2088a-qds.dtb: i2c@2000000: clock-names:0: 'ipg' was expected
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi

@@ -1004,7 +1004,7 @@ i2c0: i2c@2000000 {
 			#size-cells = <0>;
 			reg = <0x0 0x2000000 0x0 0x10000>;
 			interrupts = <0 34 0x4>; /* Level high type */
-			clock-names = "i2c";
+			clock-names = "ipg";
 			clocks = <&clockgen QORIQ_CLK_PLATFORM_PLL
 					    QORIQ_CLK_PLL_DIV(4)>;
 		};
@@ -1016,7 +1016,7 @@ i2c1: i2c@2010000 {
 			#size-cells = <0>;
 			reg = <0x0 0x2010000 0x0 0x10000>;
 			interrupts = <0 34 0x4>; /* Level high type */
-			clock-names = "i2c";
+			clock-names = "ipg";
 			clocks = <&clockgen QORIQ_CLK_PLATFORM_PLL
 					    QORIQ_CLK_PLL_DIV(4)>;
 		};
@@ -1028,7 +1028,7 @@ i2c2: i2c@2020000 {
 			#size-cells = <0>;
 			reg = <0x0 0x2020000 0x0 0x10000>;
 			interrupts = <0 35 0x4>; /* Level high type */
-			clock-names = "i2c";
+			clock-names = "ipg";
 			clocks = <&clockgen QORIQ_CLK_PLATFORM_PLL
 					    QORIQ_CLK_PLL_DIV(4)>;
 		};
@@ -1040,7 +1040,7 @@ i2c3: i2c@2030000 {
 			#size-cells = <0>;
 			reg = <0x0 0x2030000 0x0 0x10000>;
 			interrupts = <0 35 0x4>; /* Level high type */
-			clock-names = "i2c";
+			clock-names = "ipg";
 			clocks = <&clockgen QORIQ_CLK_PLATFORM_PLL
 					    QORIQ_CLK_PLL_DIV(4)>;
 		};