net: fec_mxc: support i.MX8M with CLK_CCF

Add more clks for fec_mxc according to Linux Kernel 5.4.0-rc1
drivers/net/ethernet/freescale/fec_main.c.

Since i.MX8MQ not support CLK_CCF, so add a check to restrict
the code only effect when CONFIG_IMX8M and CONFIG_CLK_CCF both defined.

Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/net/fec_mxc.h b/drivers/net/fec_mxc.h
index e5f2dd7..723b06a 100644
--- a/drivers/net/fec_mxc.h
+++ b/drivers/net/fec_mxc.h
@@ -264,6 +264,10 @@
 	u32 interface;
 #endif
 	struct clk ipg_clk;
+	struct clk ahb_clk;
+	struct clk clk_enet_out;
+	struct clk clk_ref;
+	struct clk clk_ptp;
 	u32 clk_rate;
 };