net: fec: avoid BD pointer type cast to 32bit

In aarch64 system, the BD pointer is 64bit, and the high-order 32-bits
of the address is effective, so replace usigned with (void *) type to
aovid 64bit address is casted to 32bit in .fec_enet_get_nextdesc() and
.fec_enet_get_prevdesc() functions.

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fec_main.c

@@ -235,14 +235,14 @@ static struct bufdesc *fec_enet_get_nextdesc(struct bufdesc *bdp,
 					     struct bufdesc_prop *bd)
 {
 	return (bdp >= bd->last) ? bd->base
-			: (struct bufdesc *)(((unsigned)bdp) + bd->dsize);
+			: (struct bufdesc *)(((void *)bdp) + bd->dsize);
 }
 
 static struct bufdesc *fec_enet_get_prevdesc(struct bufdesc *bdp,
 					     struct bufdesc_prop *bd)
 {
 	return (bdp <= bd->base) ? bd->last
-			: (struct bufdesc *)(((unsigned)bdp) - bd->dsize);
+			: (struct bufdesc *)(((void *)bdp) - bd->dsize);
 }
 
 static int fec_enet_get_bd_index(struct bufdesc *bdp,