thermal/int340x_thermal: Don't require IDSP to exist

The IDSP method doesn't appear to exist on the most recent Intel platforms:
instead, the IDSP data is included in the GDDV blob. Since we probably
don't want to decompress and parse that in-kernel, just allow any UUID to
be written if IDSP is missing.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Tested-by: Pandruvada, Srinivas <srinivas.pandruvada@linux.intel.com>
[ rzhang: fix checkpatch warning in changelog ]
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20200414020953.255364-3-matthewgarrett@google.com