python-m2crypto: avoid swig problem

Swig is used to generate C source and it has trouble processing opensslconf.h
sometimes. So, we help it out when multilib variants exist.

For native builds, the variant header will never exist.

Specific multi-lib header files might be named *-32.h or *-n32.h, so we check
for both names. We also might check for *-n64.h although that will never exist.
It appears that *-o??.h will never exist, so we don't check for that.

Signed-off-by: Joe Slater <jslater@windriver.com>
Signed-off-by: Chong Lu <Chong.Lu@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>