KVM: arm64: Add a composite EL2 visibility helper

KVM: arm64: Add a composite EL2 visibility helper

We are starting to have a bunch of visibility helpers checking
for EL2 + something else, and we are going to add more.

Simplify things somehow by introducing a helper that implement
extractly that by taking a visibility helper as a parameter,
and convert the existing ones to that.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241023145345.1613824-23-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>