arm, davinci_emac: fix driver bug if more then 3 PHYs are detected

since commits:
davinci: emac: add support for more than 1 PHYs
062fe7d332c28ede25626f448681e43d76bb312e

davinci: remove obsolete macro CONFIG_EMAC_MDIO_PHY_NUM
fb1d6332b5430b90a8fa8ebab709f33a60e9f816

I get following warning on the enbw_cmc board:

Err:   serial
Net:    5 ETH PHY detected
miiphy_register: non unique device name 'KSZ8873 @ 0x01'
DaVinci-EMAC
Hit any key to stop autoboot:  0

Also I see some debug printfs:

=> run load
+ emac_close
+ emac_ch_teardown
- emac_ch_teardown
+ emac_ch_teardown
- emac_ch_teardown
- emac_close
+ emac_open
- emac_open
Using DaVinci-EMAC device

reason is 062fe7d332c28ede25626f448681e43d76bb312e new define MAX_PHY.
This is set to 3! I get on this board 5 active phys, so
this leads in wrong memory writes ...

so I changed:

- define CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT to set
  the MAX_PHY value, add a description in README
  for the new CONFIG_SYS option.
- print an error message if more then MAX_PHYs are
  detected.
- fill the active_phy_addr array in a for loop with
  0xff
- changed printf() in debug_emac()

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Manjunath Hadli <manjunath.hadli@ti.com>
Cc: Prabhakar Lad <prabhakar.csengg@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Tom Rini <tom.rini@gmail.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/drivers/net/davinci_emac.c b/drivers/net/davinci_emac.c
index fa31159..36c33af 100644
--- a/drivers/net/davinci_emac.c
+++ b/drivers/net/davinci_emac.c
@@ -85,15 +85,17 @@
 /* Receive packet buffers */
 static unsigned char		emac_rx_buffers[EMAC_MAX_RX_BUFFERS * (EMAC_MAX_ETHERNET_PKT_SIZE + EMAC_PKT_ALIGN)];
 
-#define MAX_PHY		3
+#ifndef CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
+#define CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT	3
+#endif
 
 /* PHY address for a discovered PHY (0xff - not found) */
-static u_int8_t	active_phy_addr[MAX_PHY] = { 0xff, 0xff, 0xff };
+static u_int8_t	active_phy_addr[CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT];
 
 /* number of PHY found active */
 static u_int8_t	num_phy;
 
-phy_t				phy[MAX_PHY];
+phy_t				phy[CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT];
 
 static int davinci_eth_set_mac_addr(struct eth_device *dev)
 {
@@ -160,9 +162,8 @@
 	int		j;
 	unsigned int	count = 0;
 
-	active_phy_addr[0] = 0xff;
-	active_phy_addr[1] = 0xff;
-	active_phy_addr[2] = 0xff;
+	for (i = 0; i < CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT; i++)
+		active_phy_addr[i] = 0xff;
 
 	udelay(1000);
 	phy_act_state = readl(&adap_mdio->ALIVE);
@@ -175,7 +176,14 @@
 	for (i = 0, j = 0; i < 32; i++)
 		if (phy_act_state & (1 << i)) {
 			count++;
-			active_phy_addr[j++] = i;
+			if (count < CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT) {
+				active_phy_addr[j++] = i;
+			} else {
+				printf("%s: to many PHYs detected.\n",
+					__func__);
+				count = 0;
+				break;
+			}
 		}
 
 	num_phy = count;
@@ -752,7 +760,7 @@
 	if (!ret)
 		return(0);
 	else
-		printf(" %d ETH PHY detected\n", ret);
+		debug_emac(" %d ETH PHY detected\n", ret);
 
 	/* Get PHY ID and initialize phy_ops for a detected PHY */
 	for (i = 0; i < num_phy; i++) {