dvb-firmware: update to dvb-firmware-0.0.39

Signed-off-by: Stephan Raue <stephan@openelec.tv>
projects/*/linux: (re)enable userspace firmware loader support, this should fix #3083

Signed-off-by: Stephan Raue <stephan@openelec.tv>
RTL8192CU: add 050D:21F2 device id, this should fix #3081

Signed-off-by: Stephan Raue <stephan@openelec.tv>