mx6slevk: Add Ethernet support

mx6slevk has a SMSC8720 connected in RMII mode.

Add support for it.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c
index 7a29c9b..010d932 100644
--- a/arch/arm/cpu/armv7/mx6/clock.c
+++ b/arch/arm/cpu/armv7/mx6/clock.c
@@ -282,6 +282,36 @@
 	return freq / (podf + 1);
 
 }
+
+int enable_fec_anatop_clock(void)
+{
+	u32 reg = 0;
+	s32 timeout = 100000;
+
+	struct anatop_regs __iomem *anatop =
+		(struct anatop_regs __iomem *)ANATOP_BASE_ADDR;
+
+	reg = readl(&anatop->pll_enet);
+	if ((reg & BM_ANADIG_PLL_ENET_POWERDOWN) ||
+	    (!(reg & BM_ANADIG_PLL_ENET_LOCK))) {
+		reg &= ~BM_ANADIG_PLL_ENET_POWERDOWN;
+		writel(reg, &anatop->pll_enet);
+		while (timeout--) {
+			if (readl(&anatop->pll_enet) & BM_ANADIG_PLL_ENET_LOCK)
+				break;
+		}
+		if (timeout < 0)
+			return -ETIMEDOUT;
+	}
+
+	/* Enable FEC clock */
+	reg |= BM_ANADIG_PLL_ENET_ENABLE;
+	reg &= ~BM_ANADIG_PLL_ENET_BYPASS;
+	writel(reg, &anatop->pll_enet);
+
+	return 0;
+}
+
 #else
 static u32 get_mmdc_ch0_clk(void)
 {