i2c: imx: remove cpu_is_xxx by using platform_device_id

This is some amount of work left/forgot from device tree conversion.
Instead of checking cpu_is_xxx to determine the controller type, the
driver should use platform_device_id, which should match the device
tree compatible string.

The patch changes the driver to use platform_device_id rather than
cpu_is_xxx to determine the controller type/version.  It also updates
the platform code and device tree source accordingly.

As the result, mach/hardware.h inclusion gets removed from the driver.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: linux-i2c@vger.kernel.org
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index f3990b0..f604a44 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -882,7 +882,7 @@
 			i2c@021a0000 { /* I2C1 */
 				#address-cells = <1>;
 				#size-cells = <0>;
-				compatible = "fsl,imx6q-i2c", "fsl,imx1-i2c";
+				compatible = "fsl,imx6q-i2c", "fsl,imx21-i2c";
 				reg = <0x021a0000 0x4000>;
 				interrupts = <0 36 0x04>;
 				clocks = <&clks 125>;
@@ -892,7 +892,7 @@
 			i2c@021a4000 { /* I2C2 */
 				#address-cells = <1>;
 				#size-cells = <0>;
-				compatible = "fsl,imx6q-i2c", "fsl,imx1-i2c";
+				compatible = "fsl,imx6q-i2c", "fsl,imx21-i2c";
 				reg = <0x021a4000 0x4000>;
 				interrupts = <0 37 0x04>;
 				clocks = <&clks 126>;
@@ -902,7 +902,7 @@
 			i2c@021a8000 { /* I2C3 */
 				#address-cells = <1>;
 				#size-cells = <0>;
-				compatible = "fsl,imx6q-i2c", "fsl,imx1-i2c";
+				compatible = "fsl,imx6q-i2c", "fsl,imx21-i2c";
 				reg = <0x021a8000 0x4000>;
 				interrupts = <0 38 0x04>;
 				clocks = <&clks 127>;