Update qcom,saw2 node bindings with compatible strings to identify nodes
that provides cpuidle functionality for a particular SoC. Remove
unused compatible strings.

Update examples for different SAW nodes.
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Signed-off-by: NKumar Gala <galak@codeaurora.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>