bnxt_en: refactor printing of device info

The device info logged during probe will be reused by the devlink
driver_reinit code in a following patch. Extract this logic into
the new bnxt_print_device_info() function. The board index needs
to be saved in the driver context so that the board information
can be retrieved at a later time, outside of the probe function.

Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>