MAINTAINERS: add USB gadget regex to u-boot-dfu tree

We try to split work with Marek on USB as following:
- Mattijs handles USB gadget
- Marek handles the rest of USB

Add additional gadget patterns to the maintainers file so that I
get cc'ed more often on USB gadget patches.

Acked-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20240516-gadget-maintainer-v2-2-23cc916df434@baylibre.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 05217db..6d02176 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1017,8 +1017,11 @@
 F:	doc/api/dfu.rst
 F:	doc/usage/dfu.rst
 F:	drivers/dfu/
+F:	drivers/usb/*/*gadget*
 F:	drivers/usb/gadget/
 F:	include/dfu.h
+F:	include/linux/usb/ch9.h
+F:	include/linux/usb/gadget.h
 
 DRIVER MODEL
 M:	Simon Glass <sjg@chromium.org>