x86: conga-qeval20-qa3: Add SMBus support and SMSC2513 config code

This patch includes the following changes:

- Remove Designware I2C support from dts as its not used
- Configure SMBus PADs in dts
- Enable I2C commands and I2C support
- Configure SMSC2513 USB hub via SMBus upon startup
- Move environment location to match Minnowmax example
- Enhancement of the default environment

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

board/congatec/conga-qeval20-qa3-e3845/conga-qeval20-qa3.c

@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <i2c.h>
 #include <winbond_w83627.h>
 #include <asm/gpio.h>
 #include <asm/ibmpc.h>
@@ -31,3 +32,42 @@ int arch_early_init_r(void)
 {
 	return 0;
 }
+
+int board_late_init(void)
+{
+	struct udevice *dev;
+	u8 buf[8];
+	int ret;
+
+	/* Configure SMSC USB2513 USB Hub: 7bit address 0x2c */
+	ret = i2c_get_chip_for_busnum(0, 0x2c, 1, &dev);
+	if (ret) {
+		printf("Cannot find USB2513: %d\n", ret);
+		return 0;
+	}
+
+	/*
+	 * The first access to the USB Hub fails sometimes, so lets read
+	 * a dummy byte to be sure here
+	 */
+	dm_i2c_read(dev, 0x00, buf, 1);
+
+	/*
+	 * The SMSC hub is not visible on the I2C bus after the first
+	 * configuration at power-up. The following code deliberately
+	 * does not report upon failure of these I2C write calls.
+	 */
+	buf[0] = 0x93;
+	dm_i2c_write(dev, 0x06, buf, 1);
+
+	buf[0] = 0xaa;
+	dm_i2c_write(dev, 0xf8, buf, 1);
+
+	buf[0] = 0x0f;
+	dm_i2c_write(dev, 0xfa, buf, 1);
+
+	buf[0] = 0x01;
+	dm_i2c_write(dev, 0xff, buf, 1);
+
+	return 0;
+}