drm/i915/fbdev: Implement fb_dirty for intel custom fb helper

After disconnecting damage worker from update logic it's left to fbdev
emulation implementation to have fb_dirty function. Currently intel
fbdev doesn't have it. This is causing problems to features (PSR, FBC,
DRRS) relying on dirty callback.

Implement simple fb_dirty callback to deliver notifications about updates
in fb console.

v4: Add proper Fixes tag and modify commit message
v3: Check damage clip
v2: Improved commit message and added Fixes tag

Fixes: f231af49

 ("drm/fb-helper: Disconnect damage worker from update logic")
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230123074437.475103-1-jouni.hogander@intel.com