ARM: KVM: enforce maximum size for identity mapped code

We're about to move to an init procedure where we rely on the
fact that the init code fits in a single page. Make sure we
align the idmap text on a vector alignment, and that the code is
not bigger than a single page.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
MULTI POLICY LIMIT: do not export CPU0 controls. read more.

We have CPU0 always ON. so all his controls already exist, no need
to duplicate them.
we can use the already provided controls for CPU0