qemu: tpm: Run swtpm_setup --create-config-files in session mode

qemu: tpm: Run swtpm_setup --create-config-files in session mode

Using swtpm v0.7.0 we can run swtpm_setup to create default config files
for swtpm_setup and swtpm-localca in session mode. Now a user can start
a VM with an attached TPM without having to run this program on the
command line before. This program needs to run once.

This patch addresses the issue raised in
https://bugzilla.redhat.com/show_bug.cgi?id=2010649

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>