board: rockchip: rk3399: Add device tree files to MAINTAINERS

Update MAINTAINERS files for RK3399 boards to include related device
tree files. Also correct a few filenames.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/board/vamrs/rock960_rk3399/MAINTAINERS b/board/vamrs/rock960_rk3399/MAINTAINERS
index 8821672..f2121b1 100644
--- a/board/vamrs/rock960_rk3399/MAINTAINERS
+++ b/board/vamrs/rock960_rk3399/MAINTAINERS
@@ -4,8 +4,10 @@
 F:      board/vamrs/rock960_rk3399/
 F:      include/configs/rock960_rk3399.h
 F:      configs/rock960-rk3399_defconfig
+F:      arch/arm/dts/rk3399-rock960*
 
 FICUS EE
 M:      Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 S:      Maintained
 F:	configs/ficus-rk3399_defconfig
+F:	arch/arm/dts/rk3399-ficus*