drm/xe/mocs: Allow odd number of entries on test

Refactor the mocs/l3cc kunit test to support odd number of entries. This
switches out from the "check the register value" approach to check the
entry value if it makes sense from the register read. This provides an
easier output to reason about and cross check with bspec.

Some code reordering and variable re-use was also done so the 2
functions follow more or less the same logic.

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240228061048.3661978-5-lucas.demarchi@intel.com


Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>