dm: i2c: tegra: Convert to driver model

This converts all Tegra boards over to use driver model for I2C. The driver
is adjusted to use driver model and the following obsolete CONFIGs are
removed:

   - CONFIG_SYS_I2C_INIT_BOARD
   - CONFIG_I2C_MULTI_BUS
   - CONFIG_SYS_MAX_I2C_BUS
   - CONFIG_SYS_I2C_SPEED
   - CONFIG_SYS_I2C

This has been tested on:
- trimslice (no I2C)
- beaver
- Jetson-TK1

It has not been tested on Tegra 114 as I don't have that board.

Acked-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/avionic-design/common/tamonten-ng.c b/board/avionic-design/common/tamonten-ng.c
index 5870b95..86a0844 100644
--- a/board/avionic-design/common/tamonten-ng.c
+++ b/board/avionic-design/common/tamonten-ng.c
@@ -6,6 +6,7 @@
  */
 
 #include <common.h>
+#include <dm.h>
 #include <asm/arch/pinmux.h>
 #include <asm/arch/gp_padctrl.h>
 #include <asm/arch/gpio.h>
@@ -51,8 +52,15 @@
 
 void pmu_write(uchar reg, uchar data)
 {
-	i2c_set_bus_num(4);	/* PMU is on bus 4 */
-	i2c_write(PMU_I2C_ADDRESS, reg, 1, &data, 1);
+	struct udevice *dev;
+	int ret;
+
+	ret = i2c_get_chip_for_busnum(4, PMU_I2C_ADDRESS, &dev);
+	if (ret) {
+		debug("%s: Cannot find PMIC I2C chip\n", __func__);
+		return;
+	}
+	i2c_write(dev, reg, &data, 1);
 }
 
 /*