Revert "drm/fb-helper: improve DRM fbdev emulation device names"

This reverts commit b3484d2b.

That change attempted to improve the DRM drivers fbdev emulation device
names to avoid having confusing names like "simpledrmdrmfb" in /proc/fb.

But unfortunately, there are user-space programs such as pm-utils that
match against the fbdev names and so broke after the mentioned commit.

Since the names in /proc/fb are used by tools that consider it an uAPI,
let's restore the old names even when this lead to silly names like the
one mentioned above.

Fixes: b3484d2b ("drm/fb-helper: improve DRM fbdev emulation device names")
Reported-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211020165740.3011927-1-javierm@redhat.com