Replace HTTP links with HTTPS ones: Documentation/devicetree/bindings/iio

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^#

 \t\r\n]*(?:\w|/)`:
          If both the HTTP and HTTPS versions
          return 200 OK and serve the same content:
            Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com> #for Matt's drivers
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>