UPSTREAM: KVM: arm64: Reject 32bit user PSTATE on asymmetric systems

KVM does not support AArch32 EL0 on asymmetric systems. To that end,
prevent userspace from configuring a vCPU in such a state through
setting PSTATE.

It is already ABI that KVM rejects such a write on a system where
AArch32 EL0 is unsupported. Though the kernel's definition of a 32bit
system changed in commit 2122a833 ("arm64: Allow mismatched
32-bit EL0 support"), KVM's did not.

Bug: 254441685
Fixes: 2122a833 ("arm64: Allow mismatched 32-bit EL0 support")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220816192554.1455559-3-oliver.upton@linux.dev


(cherry picked from commit b10d86fb)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: Ibe2b69ec1d9aef3ed97d00aada5a9addb26f23da