drm/i915: remove display device info from i915 capabilities

Display device and display runtime info is exposed as part of
i915_display_capabilities debugfs entry. Remove this information
from i915_ capabilities as it is now reduntant.

Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231018102723.16915-3-vinod.govindapillai@intel.com