net: fec: Rename "phy-reset-active-low" property

is actually "active high". Thanks for Troy Kisky for pointing
that out.

Since the patch is in linux-next, this patch is incremental and doesn't
replace the original patch.

Signed-off-by: Bernhard Walle <bernhard@bwalle.de>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>