drm/edid: remove drm_do_get_edid()

All users of drm_do_get_edid() have been converted to
drm_edid_read_custom(). Remove the unused function to prevent new users
from creeping in.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240513202723.261440-1-jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>