sfp: warn about modules requiring address change sequence

We do not support SFP modules which require the address change sequence
as detailed by SFF 8472 revision 1.22 section 8.9.  Warn when these
modules are inserted, and treat them as SFF8079 modules for ethtool.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>