net: fec_mxc: Remove non-DM_ETH code

As DM_ETH is required for all network drivers, it's now safe to
remove the non-DM_ETH support code.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/net/fec_mxc.h b/drivers/net/fec_mxc.h
index 48faa33..77bfc1c 100644
--- a/drivers/net/fec_mxc.h
+++ b/drivers/net/fec_mxc.h
@@ -263,9 +263,7 @@
 	uint32_t reset_delay;
 	uint32_t reset_post_delay;
 #endif
-#ifdef CONFIG_DM_ETH
 	u32 interface;
-#endif
 	struct clk ipg_clk;
 	struct clk ahb_clk;
 	struct clk clk_enet_out;