drm/xe/oa: Fix kernel doc in xe_drm.h

Fix kernel doc in xe_drm.h. Also eliminate private/non-abi enum
definitions.

v2: Remove __DRM_XE_PERF_TYPE_MAX since it is unused (Michal)
v3: Also remove DRM_XE_OA_PROPERTY_MAX since it can also be
    eliminated (Michal)

Suggested-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240623203119.3840283-1-ashutosh.dixit@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>