net: mvpp2: add register modification helper

Add a helper to read-modify-write a register, and use it in the phylink
helpers.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Russell King 2020-06-20 10:21:37 +01:00 • committed by David S. Miller
commit bd45f644a8