ibm_newemac: Add ET1011c PHY support

This adds support for the Agere ET1011c PHY as found on the AMCC Taishan
board.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>