nfp: honor FW reset and loading policies

The firmware reset and loading policies can be controlled with the
combination of three hwinfo keys, 'abi_drv_reset', 'abi_drv_load_ifc'
and 'app_fw_from_flash'.

'app_fw_from_flash' defines which firmware should take precedence,
'Disk', 'Flash' or the 'Preferred' firmware. When 'Preferred'
is selected, the management firmware makes the decision on which
firmware will be loaded by comparing versions of the flash firmware
and the host supplied firmware.

'abi_drv_reset' defines when the driver should reset the firmware when
the driver is probed, either 'Disk' if firmware was found on disk,
'Always' reset or 'Never' reset. Note that the device is always reset
on driver unload if firmware was loaded when the driver was probed.

'abi_drv_load_ifc' defines a list of PF devices allowed to load FW on
the device.

Furthermore, we limit the cases to where the driver will unload firmware
again when the driver is removed to only when firmware was loaded by the
driver and only if this particular device was the only one that could
have loaded firmware. This is needed to avoid firmware being removed
while in use on multi-host platforms.

Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>