package/rpi-firmware: bump version

Fixes for:
  - sound volume
  - GL deadlock
  - ressources leak
  - compressed audio streams
  - audio sampling up to 192kHz
  - display scaling
  - cache flush for mailbox

Switch to using a 7-char cset, instead of the long one.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>