thermal: intel: int340x: Use symbolic constant for UUID comparison

thermal: intel: int340x: Use symbolic constant for UUID comparison

Replace sizeof() with a symbolic constant for UUID matching to maintain
existing ABI behavior while improving code clarity. The current behavior
of comparing only the first 7 characters is sufficient to distinguish
all UUIDs and changing to full string comparison would alter the kernel
ABI, potentially breaking existing userspace applications.

Use a defined constant to make the truncated comparison explicit and
maintainable.

Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
[ rjw: Subject adjustments ]
Link: https://patch.msgid.link/20251030035955.62171-1-kaushlendra.kumar@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>