drm/xe/display: Fix module load without display IP

When the device info initialization moved to the display part, one use
case was left behind: platforms without display IP. In order to keep the
knowledge about the display in xe_display.c, xe_display_info_init()
should be the place where this is set.

Remove the warning and set the info accordingly. This moves a later
check from  intel_device_info_runtime_init() into a very earlier one,
when no HW access is being done yet.

Fixes: 2a0f49c7 ("drm/xe/display: Move device info initialization to display")
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/20230310191430.2229799-1-lucas.demarchi@intel.com