board: rk3288: add more DT files to MAINTAINERS

A number of rk3229/rk3288 DT files are synced from Linux.
Add a maintainer to look after them and to help with
review and testing.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/board/rockchip/evb_rk3229/MAINTAINERS b/board/rockchip/evb_rk3229/MAINTAINERS
index dfa1090..4de97db 100644
--- a/board/rockchip/evb_rk3229/MAINTAINERS
+++ b/board/rockchip/evb_rk3229/MAINTAINERS
@@ -1,6 +1,8 @@
 EVB-RK3229
 M:      Kever Yang <kever.yang@rock-chips.com>
 S:      Maintained
+F:	arch/arm/dts/rk3229-evb.dts
+F:	arch/arm/dts/rk3229-evb-u-boot.dtsi
 F:      board/rockchip/evb_rk3229
 F:      include/configs/evb_rk3229.h
 F:      configs/evb-rk3229_defconfig