KVM: arm64: fix kdoc warnings in W=1 builds

Fix kdoc warnings by adding missing function parameter
descriptions or by conversion to a normal comment.

Signed-off-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240723101204.7356-3-sebott@redhat.com


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>