TPM: Add new TPMs to the tail of the list to prevent inadvertent change of dev

Add newly registered TPMs to the tail of the list, not the beginning, so that
things that are specifying TPM_ANY_NUM don't find that the device they're
using has inadvertently changed.  Adding a second device would break IMA, for
instance.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>