Bug#1076340: dolphin-emu: Add Appstream metainfo announcing HW support

[Petter Reinholdtsen]

I have also sent a patch upstream to change the ID and fix a few
validation issues with the XML file, 
<URL: https://github.com/dolphin-emu/dolphin/pull/13309 >.

Given the amount of open pull requests in the upstream project, it might
not be a good idea to wait for these to be applied before fixing the
Debian Appstream content. :)

-- 
Happy hacking
Petter Reinholdtsen