net: aquantia: replace internal driver version code with uts

As it was discussed some time previously, driver is better to
report kernel version string, as it in a best way identifies
the codebase.

Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>