net: macb: Fix ETH not found when clock not support

For the boards such as smartweb on which the clock driver isn't
supported, the ethernet fail to be found when booting up with
the below log.
---8<---
Net:   No ethernet found.
--->8---

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Heiko Schocher <hs@denx.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/macb.c b/drivers/net/macb.c
index 1c4bef9..402e866 100644
--- a/drivers/net/macb.c
+++ b/drivers/net/macb.c
@@ -113,7 +113,9 @@
 	struct mii_dev		*bus;
 
 #ifdef CONFIG_DM_ETH
+#ifdef CONFIG_CLK
 	unsigned long		pclk_rate;
+#endif
 	phy_interface_t		phy_interface;
 #endif
 };
@@ -756,7 +758,7 @@
 static u32 macb_mdc_clk_div(int id, struct macb_device *macb)
 {
 	u32 config;
-#ifdef CONFIG_DM_ETH
+#if defined(CONFIG_DM_ETH) && defined(CONFIG_CLK)
 	unsigned long macb_hz = macb->pclk_rate;
 #else
 	unsigned long macb_hz = get_macb_pclk_rate(id);
@@ -778,7 +780,7 @@
 {
 	u32 config;
 
-#ifdef CONFIG_DM_ETH
+#if defined(CONFIG_DM_ETH) && defined(CONFIG_CLK)
 	unsigned long macb_hz = macb->pclk_rate;
 #else
 	unsigned long macb_hz = get_macb_pclk_rate(id);
@@ -1002,6 +1004,7 @@
 	.write_hwaddr	= macb_write_hwaddr,
 };
 
+#ifdef CONFIG_CLK
 static int macb_enable_clk(struct udevice *dev)
 {
 	struct macb_device *macb = dev_get_priv(dev);
@@ -1025,13 +1028,13 @@
 
 	return 0;
 }
+#endif
 
 static int macb_eth_probe(struct udevice *dev)
 {
 	struct eth_pdata *pdata = dev_get_platdata(dev);
 	struct macb_device *macb = dev_get_priv(dev);
 	const char *phy_mode;
-	int ret;
 
 	phy_mode = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), "phy-mode",
 			       NULL);
@@ -1044,9 +1047,11 @@
 
 	macb->regs = (void *)pdata->iobase;
 
-	ret = macb_enable_clk(dev);
+#ifdef CONFIG_CLK
+	int ret = macb_enable_clk(dev);
 	if (ret)
 		return ret;
+#endif
 
 	_macb_eth_initialize(macb);