xbmc (Gotham): update to xbmc-57f529b, update XVBA/VDPAU patch

Signed-off-by: Stephan Raue <stephan@openelec.tv>
projects/RPi: update RPi kernel patch

Signed-off-by: Stephan Raue <stephan@openelec.tv>
Merge branch 'master' of github.com:OpenELEC/OpenELEC.tv