MAINTAINERS: add Rust device abstractions to DRIVER CORE

Add missing file path of the Rust abstractions to the maintainers entry,
until we can move it to 'drivers/base/'.

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://lore.kernel.org/r/20240619133949.64638-2-dakr@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -6714,6 +6714,7 @@ F:	include/linux/fwnode.h
 F:	include/linux/kobj*
 F:	include/linux/property.h
 F:	lib/kobj*
+F:	rust/kernel/device.rs
 
 DRIVERS FOR OMAP ADAPTIVE VOLTAGE SCALING (AVS)
 M:	Nishanth Menon <nm@ti.com>