i.MX: Fix FEC code for MDIO address selection

According to the FEC chapter of i.MX25 reference manual

When writing to MMFR register, the MDIO device and adress are selected by
bit 27 to 23 and bit 22 to 18 respectively. This is a total of 10 bits
that need to be used by the Phy chip/address decoding function.

This patch fixes the number of bits used from 9 to 10.
Signed-off-by: NJean-Christophe Dubois <jcd@tribudubois.net>
Signed-off-by: NJason Wang <jasowang@redhat.com>

hw/net/imx_fec.c

@@ -460,9 +460,9 @@ static void imx_fec_write(void *opaque, hwaddr addr,
         /* store the value */
         s->mmfr = value;
         if (extract32(value, 29, 1)) {
-            s->mmfr = do_phy_read(s, extract32(value, 18, 9));
+            s->mmfr = do_phy_read(s, extract32(value, 18, 10));
         } else {
-            do_phy_write(s, extract32(value, 18, 9), extract32(value, 0, 16));
+            do_phy_write(s, extract32(value, 18, 10), extract32(value, 0, 16));
         }
         /* raise the interrupt as the PHY operation is done */
         s->eir |= FEC_INT_MII;