docs: i2c: old-module-parameters: clarify this is for obsolete kernels

This section applies only to code for very old kernels. Avoid people
reading this unnecessarily.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/i2c/old-module-parameters.rst

@@ -2,6 +2,11 @@
 I2C device driver binding control from user-space
 =================================================
 
+.. NOTE::
+   Note: this section is only relevant if you are handling some old code
+   found in kernel 2.6. If you work with more recent kernels, you can
+   safely skip this section.
+
 Up to kernel 2.6.32, many I2C drivers used helper macros provided by
 <linux/i2c.h> which created standard module parameters to let the user
 control how the driver would probe I2C buses and attach to devices. These