MAINTAINERS: Add DT Bindings for Renesas Clock Generators

The "RENESAS CLOCK DRIVERS" section lacks the related DT bindings.
Add them.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20200417141116.23019-1-geert+renesas@glider.be

MAINTAINERS

@@ -14334,6 +14334,7 @@ M:	Geert Uytterhoeven <geert+renesas@glider.be>
 L:	linux-renesas-soc@vger.kernel.org
 S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git clk-renesas
+F:	Documentation/devicetree/bindings/clock/renesas,*
 F:	drivers/clk/renesas/
 
 RENESAS EMEV2 I2C DRIVER