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