net: atlantic: common functions needed for basic A2 init/deinit hw_ops

This patch adds common functions (mostly FW-related), which are
needed for basic A2 HW initialization / deinitialization.

Signed-off-by: Dmitry Bogdanov <dbogdanov@marvell.com>
Co-developed-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>