MAINTAINERS: Update paths for AioContext implementation

Moved by c2b38b27
("block: move AioContext, QEMUTimer, main-loop to libqemuutil")
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

MAINTAINERS

@@ -1175,8 +1175,8 @@ M: Stefan Hajnoczi <stefanha@redhat.com>
 M: Fam Zheng <famz@redhat.com>
 L: qemu-block@nongnu.org
 S: Supported
-F: async.c
-F: aio-*.c
+F: util/async.c
+F: util/aio-*.c
 F: block/io.c
 F: migration/block*
 F: include/block/aio.h