phy: add am79c874 PHY support

Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/phy/Kconfig
Simple merge

diff --cc drivers/net/phy/Makefile
Simple merge

diff --cc drivers/net/phy/amd.c
Simple merge