This patch applies the new MSR instruction to directly set the
PSTATE.SSBS bit which controls speculative loads. This new instruction
is available at Neoverse N1 core so it's utilised.

Change-Id: Iee18a8b042c90fdb72d2b98f364dcfbb17510728
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>

Change-Id: Ideb49011da35f39ff1959be6f5015fa212ca2b6b
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>

Change-Id: I0bb5aca9bb272332340b5baefc473a01f8a27896
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>