net: calxeda xgmac ethernet driver add missing HAS_IOMEM dependency

Fix allyesconfig build on architectures without IOMEM:

drivers/net/ethernet/calxeda/xgmac.c:1800:2:
  error: implicit declaration of function 'iounmap' [-Werror=implicit-function-declaration]

Signed-off-by: Heiko Carstens <[email protected]>
Cc: Rob Herring <[email protected]>
Acked-by: Rob Herring <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
1 file changed