drm/xe/guc: Default log level to non-verbose

drm/xe/guc: Default log level to non-verbose

Currently xe sets the guc log level to a verbose level since it's useful
to debug hangs and general development. However the verbose level may
already be too much and affect performance.

Michal Mrozek did some tests with the L0 compute stack for submission
latency with ULLS disabled. Below are the normalized numbers with log
level 3 (the current default) as baseline for each test:

                          Test \ Log Level                        3      0      1      2
 ----------------------------------------------------------- ------ ------ ------ ------
  BestWalkerNthCommandListSubmission(CmdListCount=2)           1.00   0.63   0.63   0.96
  BestWalkerNthSubmission(KernelCount=2)                       1.00   0.62   0.63   0.96
  BestWalkerNthSubmissionImmediate(KernelCount=2)              1.00   0.58   0.58   0.85
  BestWalkerSubmission                                         1.00   0.62   0.62   0.96
  BestWalkerSubmissionImmediate                                1.00   0.63   0.62   0.96
  BestWalkerSubmissionImmediateMultiCmdlists(cmdlistCount=2)   1.00   0.58   0.58   0.86
  BestWalkerSubmissionImmediateMultiCmdlists(cmdlistCount=4)   1.00   0.70   0.70   0.83
  BestWalkerSubmissionImmediateMultiCmdlists(cmdlistCount=8)   1.00   0.53   0.52   0.78

Log level 2 is the first "verbose level" for GuC, where the biggest
difference happens. Keep log level 3 for CONFIG_DRM_XE_DEBUG, but switch
to 1, i.e.  GUC_LOG_LEVEL_NON_VERBOSE, for "normal" builds.

Cc: Michal Mrozek <michal.mrozek@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://lore.kernel.org/r/20250613-guc-log-level-v2-1-cb84a63e49fe@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>