drm/xe/pf: Add support for enabling scheduler groups

drm/xe/pf: Add support for enabling scheduler groups

Scheduler groups are enabled by sending a specific policy configuration
KLV to the GuC. We don't allow changing this policy if there are VF
active, since the expectation is that the VF will only check if the
feature is enabled during driver initialization.

While the GuC interface supports a maximum of 8 groups, the actual
number of groups that can be enabled can be lower than that and
can be different on different devices. For now, all devices support up
to 2 groups, so we check that we do not have more groups than that.

The functions added by this patch will be used by sysfs/debugfs, coming
in follow up patches.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patch.msgid.link/20251218223846.1146344-18-daniele.ceraolospurio@intel.com