net/mlx5: Add support for FW fatal reporter dump

Add support of dump callback for mlx5 FW fatal reporter.
The FW fatal dump uses cr-dump functionality to gather cr-space data for
debug. The cr-dump uses vsc interface which is valid even if the FW
command interface is not functional, which is the case in most FW fatal
errors.

Command example and output:
$ devlink health dump show pci/0000:82:00.0 reporter fw_fatal
 crdump_data:
  00 20 00 01 00 00 00 00 03 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 ba 82 00 00
  0c 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 fa 00
  a4 0e 00 00 00 00 00 00 80 c7 fe ff 50 0a 00 00
...
...

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>