docs: i2c: convert to ReST and add to driver-api bookset

Convert each file at I2C subsystem, renaming them to .rst and
adding to the driver-api book.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index f26ed49..2e6dcf8 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -2206,7 +2206,7 @@ static int i2c_detect_address(struct i2c_client *temp_client,
 			dev_warn(&adapter->dev,
 				"This adapter will soon drop class based instantiation of devices. "
 				"Please make sure client 0x%02x gets instantiated by other means. "
-				"Check 'Documentation/i2c/instantiating-devices' for details.\n",
+				"Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
 				info.addr);
 
 		dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
@@ -2236,7 +2236,7 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
 	if (adapter->class == I2C_CLASS_DEPRECATED) {
 		dev_dbg(&adapter->dev,
 			"This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
-			"If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n",
+			"If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
 			driver->driver.name);
 		return 0;
 	}