Merge branch 'mlxsw-fw_load_policy'

Ido Schimmel says:

====================
mlxsw: Add 'fw_load_policy' devlink parameter

Shalom says:

Currently, drivers do not have the ability to control the firmware
loading policy and they always use their own fixed policy. This prevents
drivers from running the device with a different firmware version for
testing and/or debugging purposes. For example, testing a firmware bug
fix.

For these situations, the new devlink generic parameter,
'fw_load_policy', gives the ability to control this option and allows
drivers to run with a different firmware version than required by the
driver.

Patch #1 adds the new parameter to devlink. The other two patches, #2
and #3, add support for this parameter in the mlxsw driver.

Example:
  # Query the devlink parameters supported by the device
    $ devlink dev param show
    pci/0000:03:00.0:
      name fw_load_policy type generic
        values:
          cmode driverinit value driver

  # Flash new firmware using ethtool
    $ ethtool -f swp1 mellanox/mlxsw_spectrum-13.1703.4.mfa2

  # Toggle parameter
    $ devlink dev param set pci/0000:03:00.0 name fw_load_policy value flash cmode driverinit

  # devlink reset
    $ devlink dev reload pci/0000:03:00.0

  # Query firmware version to show changes took affect
    $ ethtool -i swp1
    driver: mlxsw_spectrum
    version: 1.0
    firmware-version: 13.1703.4
    expansion-rom-version:
    bus-info: 0000:03:00.0
    supports-statistics: yes
    supports-test: no
    supports-eeprom-access: no
    supports-register-dump: no
    supports-priv-flags: no

iproute2 patches available here:
https://github.com/tshalom/iproute2-next

v2:
* Change 'fw_version_check' to 'fw_load_policy' with values 'driver' and
  'flash' (Jakub)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>