Musl only specifies in/outb for x86/x86. Use the fallback path in case
musl is used.

This should fail compilation during the linking stage but for some reason
does not. Will do if -Werror=implicit-function-declaration is specified.

Fixed up license information.

Other small cleanups.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Build timestamp prevents reproducible builds [0].

[0] https://reproducible-builds.org/docs/timestamps/

Signed-off-by: Alexander Couzens <lynxis@fe80.eu>