As the comments from Heiko Stuebner <heiko@sntech.de> that compatible
should not contain any placeholders, this patch fix it for rk3228 SoC.

Note that this is a fix for v4.13, due to fixing the current non-standard
binding name that should not become part of an official kernel release.
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>