Add support for XM with ADPCM samples

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
[test] Add loader test for XM with ADPCM samples

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Update changelog

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>