board: freescale: Refactor NXP common mux code

Refactors similar mux code from multiple NXP boards into a common location,
and allows it to be disabled in config.

New config: CONFIG_FSL_USE_PCA9547_MUX to enable PCA9547 mux functionality.

Signed-off-by: Stephen Carlson <stcarlso@linux.microsoft.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/board/freescale/common/i2c_common.h b/board/freescale/common/i2c_common.h
new file mode 100644
index 0000000..840ad66
--- /dev/null
+++ b/board/freescale/common/i2c_common.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2014 Freescale Semiconductor, Inc.
+ * Copyright 2020-21 NXP
+ * Copyright 2021 Microsoft Corporation
+ */
+
+#ifndef __NXP_I2C_COMMON_H__
+#define __NXP_I2C_COMMON_H__
+
+/* Common functionality shared by the I2C drivers for VID and the mux. */
+#ifdef CONFIG_DM_I2C
+#define DEVICE_HANDLE_T struct udevice *
+
+#define I2C_READ(dev, register, data, length) \
+	dm_i2c_read(dev, register, data, length)
+#define I2C_WRITE(dev, register, data, length) \
+	dm_i2c_write(dev, register, data, length)
+#else
+#define DEVICE_HANDLE_T int
+
+#define I2C_READ(dev, register, data, length) \
+	i2c_read(dev, register, 1, data, length)
+#define I2C_WRITE(dev, register, data, length) \
+	i2c_write(dev, register, 1, data, length)
+#endif
+
+int fsl_i2c_get_device(int address, int bus, DEVICE_HANDLE_T *dev);
+
+#endif