KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set

KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set

Reset the VCPU with PSTATE.M = EL2h when the nested virtualization
feature is enabled on the VCPU.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[maz: rework register reset not to use empty data structures]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-5-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>