buildroot

package/mpd: drop dependency on libglib2

Version 0.20.x does not depend on libglib2 anymore. Note, that the
dependency on MMU and Thread remain, as MPD uses fork() and thread
functionality.

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>