net: aquantia: add support for PIN funcs

Depending on FW configuration we can manage from 0 to 3 PINs for periodic output
and from 0 to 1 ext ts PIN for getting TS for external event.

Ext TS PIN functionality is implemented via periodic timestamps polling
directly from PHY, because right now there is now way to receive the
PIN trigger interrupt from phy.

The polling interval is 15 milliseconds.

Co-developed-by: Egor Pomozov <epomozov@marvell.com>
Signed-off-by: Egor Pomozov <epomozov@marvell.com>
Co-developed-by: Pavel Belous <pavel.belous@aquantia.com>
Signed-off-by: Pavel Belous <pavel.belous@aquantia.com>
Signed-off-by: Dmitry Bezrukov <dmitry.bezrukov@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>