drm/xe/xe2: synchronise CS_CHICKEN1 with WMTP support

Recommendation is to read FUSE4 register to check if WMTP has been
enabled/disabled by HW. If enabled we don't need to do anything special,
however if disabled recommendation is to also disable the WMTP mode in
the FF_SLICE_CS_CHICKEN2 register, falling back to thread-group and
mid-batch preemption only. However on Linux, the per-context CS_CHICKEN1
is how userspace controls pre-emption, so instead use the default lrc to
disable WMTP using CS_CHICKEN1, if disabled by HW. Userspace is still
free to set CS_CHICKEN1 to whatever they want later.

v2: remove redundant version check and also add descriptive name(Matt)
v3: remove usage of REG_FIELD_GET(Matt)

Cc: Matt Roper <matthew.d.roper@intel.com>
Co-developed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20240104182615.21327-1-nirmoy.das@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>