MAINTAINERS: Devicetree: Exclude test bindings

Devicetree maintainers probably do not need to be pulled in for
dts/bindings/ folders that are found in various tests and samples
directories, the purpose of these lines was only for the top level
dts/bindings/ folder.

Signed-off-by: Declan Snyder <[email protected]>

Author: Declan Snyder

MAINTAINERS.yml

@@ -896,8 +896,8 @@ Devicetree:
     - galak
     - rruuaanng
   files-regex:
-    - dts/bindings/.*zephyr.*
-    - dts/bindings/[^,]+$
+    - ^dts/bindings/.*zephyr.*
+    - ^dts/bindings/[^,]+$
   files:
     - scripts/dts/
     - dts/common/