Revert "Better Hardware Virt Support checking"

is_virtual_packstack custom fact checks if packstack is running on a
virtualized system. So checking for 'vmx' or 'svm' flags is useless !

This reverts commit 5c357a8dd3c04a4eac7f9a106ae64ea5bc38eecc.

Change-Id: I81f9444a787712cb1c5e676256d6a7c6ebdf84bf