net/mlx5: FPGA, Add SBU bypass and reset flows

The Innova FPGA includes shell hardware and Sandbox-Unit (SBU) hardware.
The shell hardware is handled by mlx5_core itself, while the SBU is
handled by a client driver.

Reset the SBU to a well-known initial state when initializing a new
device, and set the FPGA to bypass mode when uninitializing a device.
This allows the client driver to assume that its device has been
reset when a new device is detected.

During SBU reset, the FPGA is put into SBU-bypass mode. In this mode
packets do not pass through the SBU, so it cannot affect the network
data stream at all.

A factory-image does not have an SBU, so skip these flows.

Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>