arm/arm64: KVM: Implement PSCI 1.0 support

arm/arm64: KVM: Implement PSCI 1.0 support

BugLink: http://bugs.launchpad.net/bugs/1751064
Commit 58e0b2239a4d upstream.

PSCI 1.0 can be trivially implemented by providing the FEATURES
call on top of PSCI 0.2 and returning 1.0 as the PSCI version.

We happily ignore everything else, as they are either optional or
are clarifications that do not require any additional change.

PSCI 1.0 is now the default until we decide to add a userspace
selection API.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>