drm/panfrost: Print RSS for tiler heap BO's in debugfs GEMS file

Otherwise it would display the virtual allocation size, which is often
much bigger than the RSS.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Fixes: e48ade5e ("drm/panfrost: show device-wide list of DRM GEM objects over DebugFS")
Tested-by: Christopher Healy <healych@amazon.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250808010235.2831853-1-adrian.larumbe@collabora.com