Create helpers mii_read32 / mii_write32 for 32 bit MII ops.
Rename r3 variable to page in ar8xxx_mii_write to make it consistent
with the other ar8xxx_mii_xxxx functions.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@43741 3c298f89-4303-0410-b956-a3cf2f4a3e73