Create a configuration option for autonomous random drivers, i.e. PSA
crypto drivers that provide a random generator, that have their own
entropy source and do not support injecting entropy from another
source.
This commit only creates the configuration option. Subsequent commits
will add the implementation and tests.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
f08b3f8624