We are not detecting the presence of FIPS from QEMU, but from procfs and
that means it's not QEMU capability. It was decided that we will pass
this flag to QEMU even if it's not supported by old QEMU binaries.

This patch also reverts changes done by commit a21cfb0f to
qemucapabilitestest and implements a new test case in qemuxml2argvtest.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1135431Signed-off-by: NPavel Hrdina <phrdina@redhat.com>