vga_switcheroo: Sphinxify docs

Fix up formatting glitches remaining after the automatic rst conversion.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/3a369602ae35fdbf5e4a12f7e172088c89fa27bb.1468225027.git.lukas@wunner.de