fsl_i2c: Added a callpoint for i2c_board_late_init

This patch adds a callpoint in i2c_init that allows board specific
i2c board initialization (typically for i2c bus reset) that is called
after i2c_init operations, allowing the i2c_board_late_init function
to use the pre-configured i2c bus speed and slave address.
diff --git a/include/i2c.h b/include/i2c.h
index d828964..cd23c8a 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -111,6 +111,9 @@
 #ifdef CONFIG_SYS_I2C_INIT_BOARD
 void i2c_init_board(void);
 #endif
+#ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
+void i2c_board_late_init(void);
+#endif
 
 #if defined(CONFIG_I2C_MUX)