stmmac: add the experimental PCI support

This patch adds the PCI support (as EXPERIMENTAL)
this has been also tested on XLINX XC2V3000 FF1152AMT0221
D1215994A VIRTEX FPGA board.
To support the PCI bus the main part has been reworked
and both the platform and the PCI specific parts have
been moved into different files.

Signed-off-by: Rayagond Kokatanur <rayagond@vayavyalabs.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
index e250935..f20aa12 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
@@ -238,6 +238,19 @@
 	writel(data, ioaddr + low);
 }
 
+/* Enable disable MAC RX/TX */
+void stmmac_set_mac(void __iomem *ioaddr, bool enable)
+{
+	u32 value = readl(ioaddr + MAC_CTRL_REG);
+
+	if (enable)
+		value |= MAC_RNABLE_RX | MAC_ENABLE_TX;
+	else
+		value &= ~(MAC_ENABLE_TX | MAC_RNABLE_RX);
+
+	writel(value, ioaddr + MAC_CTRL_REG);
+}
+
 void stmmac_get_mac_addr(void __iomem *ioaddr, unsigned char *addr,
 			 unsigned int high, unsigned int low)
 {