iwlwifi: dump api version in yaml format

Used for debugging what FW API we are using to understand misalignment
with API changes.

The output looks like this as a yaml format

fw_api_ver:
  0x0001:
    name: MVM_ALIVE
    cmd_ver: 99
    notif_ver: 4
  0x0108:
    name: PHY_CONTEXT_CMD
    cmd_ver: 2
    notif_ver: 0
...

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200424194456.18bf540ab8e0.I6217488f1740f0e6accd0cecd09dfd46bad88426@changeid