Measured boot: Use a fixed stateless handle

The measured boot service is called from outside TF-M using the
stateless handle. Since TF-M can be updated separately from the rest of
the system, use a fixed stateless handle so it cannot change in an
update.

Signed-off-by: Jamie Fox <jamie.fox@arm.com>
Change-Id: I1d0dcf86d286e357832d8b193d25e669e072b1d3
1 file changed