ARM: psci: Fix indentation in DT bindings

Fix bogus indentation of the PSCI compatible values, reformat.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>