qemu_tpm: Extend start/stop APIs

qemu_tpm: Extend start/stop APIs

This is basically just a continuation of the previous commit.
Now that the security driver APIs have a boolean flag that
controls setting/restoring seclabel of either both TPM state and
log files, or just the log file, propagate this boolean into
those APIs that start/stop swtpm emulator. For now, just pass
true. The juicy bits are soon to come.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>