MAINTAINERS: Add entry for fieldbus subsystem

Add myself as the maintainer of the fieldbus subsystem.
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -14906,6 +14906,12 @@ L:	linux-erofs@lists.ozlabs.org
 S:	Maintained
 F:	drivers/staging/erofs/
 
+STAGING - FIELDBUS SUBSYSTEM
+M:	Sven Van Asbroeck <TheSven73@gmail.com>
+S:	Maintained
+F:	drivers/staging/fieldbus/*
+F:	drivers/staging/fieldbus/Documentation/
+
 STAGING - INDUSTRIAL IO
 M:	Jonathan Cameron <jic23@kernel.org>
 L:	linux-iio@vger.kernel.org