net: phy: at803x: add DAC amplitude fix for 8327 phy

QCA8327 internal phy require DAC amplitude adjustement set to +6% with
100m speed. Also add additional define to report a change of the same
reg in QCA8337. (different scope it does set 1000m voltage)
Add link_change_notify function to set the proper amplitude adjustement
on PHY_RUNNING state and disable on any other state.

Fixes: b4df02b5

 ("net: phy: at803x: add support for qca 8327 A variant internal phy")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>