Add privacy switches to sysfs (#14)

I've added querying the mic and camera privacy switches
through sysfs
(`/sys/devices/platform/framework_laptop/framework_privacy`).

There doesn't really seem to be a proper standard for this, but I've
kept to the same [format as the `dell-privacy`
driver](https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-platform-dell-privacy-wmi),
so if there is scripts or something floating around for dell laptops, it
should be a one or two line change for framework laptops too.

Also don't feel pressured to merge this or anything, it seems way less
useful than fan control, and I mostly just did it to procrastinate doing
an assignment haha.

I've also added a few basically trivial changes to do with my previous
PR.