board: rk3288: simplify the DT file list in MAINTAINERS

Use a wildcard to simplify the list of board DT files in the MAINTAINERS
file for the Radxa Rock 2 Square board.

Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/board/radxa/rock2/MAINTAINERS b/board/radxa/rock2/MAINTAINERS
index 5328fd7..af974c9 100644
--- a/board/radxa/rock2/MAINTAINERS
+++ b/board/radxa/rock2/MAINTAINERS
@@ -1,9 +1,7 @@
 FIREFLY
 M:	Simon Glass <sjg@chromium.org>
 S:	Maintained
-F:	arch/arm/dts/rk3288-rock2-som.dtsi
-F:	arch/arm/dts/rk3288-rock2-square.dts
-F:	arch/arm/dts/rk3288-rock2-square-u-boot.dtsi
+F:	arch/arm/dts/rk3288-rock2*
 F:	board/radxa/rock2
 F:	include/configs/rock2.h
 F:	configs/rock2_defconfig