docs: hwmon: (ltc2945) update datasheet link

Old one isn't working anymore. Update to the latest datasheet link.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201005131226.1774081-1-alexandru.ardelean@analog.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

docs: hwmon: Add an index file and rename docs to *.rst

Now that all files were converted to ReST format, rename them
and add an index.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>