On a freescale imx6q platform, a hardware phy chip KSZ9021 is
recognized as a KS8001 chip by the current driver like this:
eth0: Freescale FEC PHY driver [Micrel KS8001 or KS8721]

KSZ9021 has phy_id 0x00221610, while KSZ8001 has phy_id
0x0022161a, the current phy_id_mask (0x00fffff0/0x00ffff10) can't
distinguish them. So change phy_id_mask to resolve this problem.

Although the micrel datasheet says that the 4 LSB of phyid2 register
contains the chip revision number and the current driver is designed
to follow this rule, in reality the chip implementation doesn't follow
it.

Cc: David J. Choi <david.choi@micrel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Hui Wang <jason77.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>