net: smsc: remove build warning of duplicate definition

The build of m32r was giving warning:

In file included from drivers/net/ethernet/smsc/smc91x.c:92:0:
drivers/net/ethernet/smsc/smc91x.h:448:0: warning: "SMC_inb" redefined
 #define SMC_inb(ioaddr, reg)  ({ BUG(); 0; })

drivers/net/ethernet/smsc/smc91x.h:106:0:
	note: this is the location of the previous definition
 #define SMC_inb(a, r)  inb(((u32)a) + (r))

drivers/net/ethernet/smsc/smc91x.h:449:0: warning: "SMC_outb" redefined
 #define SMC_outb(x, ioaddr, reg) BUG()

drivers/net/ethernet/smsc/smc91x.h:108:0:
	note: this is the location of the previous definition
 #define SMC_outb(v, a, r) outb(v, ((u32)a) + (r))

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>