thermal: imx_tmu: Add support for thermal sensor on iMX8MM

The analog sensors on iMX8MM are new, used for 14LPP process. So the
Temperature Sensor Monitoring Unit (TMU) has some change accordingly.
We use version 2 in TMU driver to represent the new TMU, so the one
driver can service for both i.MX8MQ/M.

Signed-off-by: Peng Fan <peng.fan@nxp.com>