nvidia: fix GP107 signed firmware

It has been reported that the GP107 firmware would not pass signature
verification due to the wrong files being released. Replace them with
the proper files.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

nvidia/gp107/gr/fecs_bl.bin

-../../gp102/gr/fecs_bl.bin
\ No newline at end of file

nvidia/gp107/gr/gpccs_bl.bin

-../../gp102/gr/gpccs_bl.bin
\ No newline at end of file