i.MX6DL: mamoj: Add I2C support

i.MX6DL Mamoj has i2c3 and i2c4 buses, add support
through DM_I2C with dt definition.

i2c log:
Reviewed-by: Stefano Babic <sbabic@denx.de>

=======
=> i2c bus
Bus 2:  i2c@021a8000
Bus 3:  i2c@021f8000
=> i2c dev 2
Setting bus to 2
=> i2c speed 400000
Setting bus speed to 400000 Hz
=> i2c probe
Valid chip addresses: 20 51 53
=> i2c md 53 0xff
00ff: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
=> i2c md 51 0xff
00ff: a8 08 40 50 09 43 46 52 42 18 80 8e ae a9 d0 53    ..@P.CFRB......S
=> i2c dev 3
Setting bus to 3
=> i2c speed 100000
Setting bus speed to 100000 Hz
=> i2c probe
Valid chip addresses: 08 40 48 4B
=> i2c md 08 0xff
00ff: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Simone CIANNI <simone.cianni@bticino.it>
Signed-off-by: Raffaele RECALCATI <raffaele.recalcati@bticino.it>
diff --git a/arch/arm/dts/imx6dl-mamoj.dts b/arch/arm/dts/imx6dl-mamoj.dts
index 068d518..5580434 100644
--- a/arch/arm/dts/imx6dl-mamoj.dts
+++ b/arch/arm/dts/imx6dl-mamoj.dts
@@ -21,6 +21,20 @@
 	status = "okay";
 };
 
+&i2c3 {
+	clock-frequency = <400000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_i2c3>;
+	status = "okay";
+};
+
+&i2c4 {
+	clock-frequency = <100000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_i2c4>;
+	status = "okay";
+};
+
 &uart3 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_uart3>;
@@ -60,6 +74,20 @@
 		>;
 	};
 
+	pinctrl_i2c3: i2c3grp {
+		fsl,pins = <
+			MX6QDL_PAD_GPIO_3__I2C3_SCL     0x4001b8b1
+			MX6QDL_PAD_GPIO_6__I2C3_SDA     0x4001b8b1
+		>;
+	};
+
+	pinctrl_i2c4: i2c4grp {
+		fsl,pins = <
+			MX6QDL_PAD_GPIO_7__I2C4_SCL	0x4001b8b1
+			MX6QDL_PAD_GPIO_8__I2C4_SDA	0x4001b8b1
+		>;
+	};
+
 	pinctrl_uart3: uart3grp {
 		fsl,pins = <
 			MX6QDL_PAD_EIM_D24__UART3_TX_DATA	0x1b0b1