buildroot

libmpdclient: bump to version 2.14

Since version 2.13 libmpdclient only supports the meson build.
Therefore, adapt to package infrastructure according to the user manual.

Also add a hash for the license file.

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