MAINTAINERS: add include/dt-bindings/phy to GENERIC PHY FRAMEWORK

Maintainers of the directory Documentation/devicetree/bindings/phy
are also the maintainers of the corresponding directory
include/dt-bindings/phy.

Add the file entry for include/dt-bindings/phy to the appropriate
section in MAINTAINERS.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220613122621.18397-1-lukas.bulwahn@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

MAINTAINERS

@@ -8308,6 +8308,7 @@ Q:	https://patchwork.kernel.org/project/linux-phy/list/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy.git
 F:	Documentation/devicetree/bindings/phy/
 F:	drivers/phy/
+F:	include/dt-bindings/phy/
 F:	include/linux/phy/
 
 GENERIC PINCTRL I2C DEMULTIPLEXER DRIVER