ARM: Do 15e0d9e3 (ARM: pm: let platforms select cpu_suspend support) properly

Let's do the changes properly and fix the same problem everywhere, not
just for one case.

Cc: <stable@vger.kernel.org> # kernels containing 15e0d9e3 or equivalent
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>