drm/xe/vf: Don't register I2C devices if VF

drm/xe/vf: Don't register I2C devices if VF

VF drivers can't access I2C devices, so skip their registration when
running as VF.

Signed-off-by: Lukasz Laguna <lukasz.laguna@intel.com>
Fixes: f0e53aadd702 ("drm/xe: Support for I2C attached MCUs")
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://lore.kernel.org/r/20250717155420.25298-1-lukasz.laguna@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 9a220e065914b67b55d3d0ab91c3e215742fdd73)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>