Fixes for the FreeBSD build.

This changes were required to get x86info actually build on FreeBSD stable/10 amd64.
I did not implemented the cpuid-freebsd.c:bind_cpu() (yet ?).
The lsmsr utility is also not ported.

fls() function conflicts with the same function provided by the FreeBSD libc and strings.h header.
I opted to just rename the local function instead of conditionally use of the system-provided one.

I can split this into more fine-grained chunks if you prefer.