drm/xe/vf: Don't enable hwmon if VF

Registers used by hwmon are not available for VF drivers.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240213154355.1221-7-michal.wajdeczko@intel.com