Limiting loading of PKCS#11 by architecture

[Stef Walter]

When packaging on Fedora, Kalev Lember brought up the issue that there's
not really a way to limit p11-kit to only load modules for a given
architecture.

When both 64-bit and 32-bit versions of a PKCS#11 library are installed
then 64-bit processes should only load 64-bit modules, and vice versa.

I've put together a solution here:

https://bugs.freedesktop.org/show_bug.cgi?id=40775

I'm hoping to get this into p11-kit shortly, and have a new release. A
bunch of distro's are releasing soon, so this would help make things work.

Let me know if you see any issues.

Cheers

Stef