thermal: int340x: Mode setting with new OS handshake

With the new OS handshake introduced by commit: "c7ff2976 ("thermal:
int340x: Update OS policy capability handshake")", the "enabled" thermal
zone mode doesn't work in the same way as previously.

The "enabled" mode fails with -EINVAL when the new handshake is used.

To address this issue, when the new OS UUID mask is set:

 - When the mode is "enabled", return 0 as the firmware already has the
   latest policy mask.

 - When the mode is "disabled", update the firmware with the UUID mask
   of zero.

This way, the firmware can take over the thermal control.

Also reset the OS UUID mask, which allows user space to update with new
set of policies.

Fixes: c7ff2976 ("thermal: int340x: Update OS policy capability handshake")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Changelog edits, removed unneeded parens ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>