smsc: smc911x: Fix sparse warnings

smsc: smc911x: Fix sparse warnings

ioremap returns 'void __iomem *' type.

Fix the following build warnings:

drivers/net/ethernet/smsc/smc911x.c:2079:14: warning: incorrect type in assignment (different address spaces)
drivers/net/ethernet/smsc/smc911x.c:2079:14:    expected unsigned int *addr
drivers/net/ethernet/smsc/smc911x.c:2079:14:    got void [noderef] <asn:2>*
drivers/net/ethernet/smsc/smc911x.c:2086:18: warning: incorrect type in assignment (different address spaces)
drivers/net/ethernet/smsc/smc911x.c:2086:18:    expected void [noderef] <asn:2>*base
drivers/net/ethernet/smsc/smc911x.c:2086:18:    got unsigned int *addr
drivers/net/ethernet/smsc/smc911x.c:2091:25: warning: incorrect type in argument 1 (different address spaces)
drivers/net/ethernet/smsc/smc911x.c:2091:25:    expected void volatile [noderef] <asn:2>*addr
drivers/net/ethernet/smsc/smc911x.c:2091:25:    got unsigned int *addr

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>