Add the mlxfw module for Mellanox firmware flash process

Add the mlxfw module for Mellanox firmware flash process

The mlxfw module is in charge of common logic needed to flash Mellanox
devices firmware, which consists of:
 - Parse the Mellanox Firmware Archive version 2 (MFA2) format, which is
   the format used to store the Mellanox firmware. The MFA2 format file can
   hold firmware for many different silicon variants, differentiated by a
   unique ID called PSID. In addition, the MFA2 file data section is
   compressed using xz compression to save both file-system space and
   memory at extraction time.
 - Implement the firmware flash state machine logic, which is a common
   logic for Mellanox products needed to flash the firmware to the device.

As the module is shared between different Mellanox products, it defines a
set of callbacks to be implemented by the specific driver for hardware
interaction.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>