ar9170: added phy register initialisation from eeprom values

This patch adds the initialisation of some PHY registers
from the modal_header[] values in the EEPROM
(see otus/hal/hpmain.c, line 333 ff.)

Signed-off-by: Joerg Albert <jal2@gmx.de>
Acked-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>