feat(realm_payload): use random start REC

This patch modifies tests below
host_test_realm_create_enter
host_test_multiple_realm_create_enter
host_realm_multi_rec_single_cpu
to start Realm execution with a random REC number.

Change-Id: I5961f953efc4dab25d301a7026d0c3949701df4a
Signed-off-by: AlexeiFedorov <Alexei.Fedorov@arm.com>
2 files changed