Fix 6.12 for realzy

New Alpine 3.21 ships with 6.12 kernels. My previous attempt was a failure...because I didn't test it on 6.12 🤣

Fix building on Linux 6.12

Apparently rdtsc() was being pulled in indirectly before...and somehow being defined on 3.10 (for Centos 7). Mysteries abound!

0.2.0 - Centos 7 Support

Adds more silly #ifdef's to support older Linux kernels like the 3.10 line used in Centos 7.

Wild VMM_CLOCK appeared!

It's super effective!