drm/i915/fb: convert intel_fbdev.[ch] and intel_fbdev_fb.[ch] to struct intel_display
Going forward, struct intel_display is the main display device data
pointer. Convert intel_fbdev.[ch] and as much as possible of
intel_fbdev_fb.[ch] to struct intel_display.
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Link: https://lore.kernel.org/r/49651754f3716041f97984e47c15d331851870a5.1744222449.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>