package/rpi-firmware: bump revision

Fixes in firmware:
  - misc: SDRAM calibration
  - camera: burst performance, exposure, EXIF
  - audio: noise in multichannel output, 8-bit input, float input/output,
           non-power-of-2 multi-channel
  - video: SEI in h264 encoder

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>