hwmon: prefix kernel-doc comments for structs with struct

hwmon: prefix kernel-doc comments for structs with struct

The command ./scripts/kernel-doc -none include/linux/hwmon.h warns:

  include/linux/hwmon.h:406: warning: This comment starts with '/**', but
    isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
   * Channel information
  include/linux/hwmon.h:425: warning: This comment starts with '/**', but
    isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
   * Chip configuration

Address those kernel-doc warnings by prefixing kernel-doc descriptions for
structs with the keyword 'struct'.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20211216154257.26758-1-lukas.bulwahn@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>