net: fman: fix build errors when linux/phy*.h is removed from net/dsa.h

drivers/net/ethernet/freescale/fman/fman_memac.c:519:21: error: dereferencing pointer to incomplete type 'struct fixed_phy_status'

Add linux/phy_fixed.h to fman_memac.c

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>