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.