cpuidle: arm: Enable compile testing for some of drivers

Some of cpuidle drivers for ARMv7 can be compile tested on this
architecture because they do not depend on mach-specific bits.  Enable
compile testing for big.LITTLE, Kirkwood, Zynq, AT91, Exynos and mvebu
cpuidle drivers.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>