Documentation/acpi/gpio.md: Fix markdown heading levels

Only the document title should be a top-level heading ('#'). Everything
else should be a second- over lower-level heading ('##').

Also remove the '#' sign at the end of heading lines. "# Foo #" is
mentioned as a valid syntax variant at [1], but it's quite uncommon.

[1]: https://daringfireball.net/projects/markdown/syntax#header

Change-Id: Ida16c3ecaa22e8439007673cb943d04952e19471
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/25678
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed