MAINTAINERS: remove mengxianglinx from USB collaborators

mengxianglinx is not a USB collaborator.

Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>

Author: jfischer-no

MAINTAINERS.yml

@@ -1524,8 +1524,6 @@ USB:
     status: maintained
     maintainers:
         - jfischer-no
-    collaborators:
-        - mengxianglinx
     files:
         - drivers/usb/
         - dts/bindings/usb/