net: fec_mxc: not access reserved register on i.MX8

We should not access reserved register on i.MX8, otherwise met SERROR

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index a672250..d7c0809 100644
--- a/drivers/net/fec_mxc.c
+++ b/drivers/net/fec_mxc.c
@@ -604,7 +604,7 @@
 	writel(0x00000000, &fec->eth->gaddr2);
 
 	/* Do not access reserved register */
-	if (!is_mx6ul() && !is_mx6ull() && !is_imx8m()) {
+	if (!is_mx6ul() && !is_mx6ull() && !is_imx8() && !is_imx8m()) {
 		/* clear MIB RAM */
 		for (i = mib_ptr; i <= mib_ptr + 0xfc; i += 4)
 			writel(0, i);