If CONFIG_PM=y, cc_pm_is_dev_suspended() is just a wrapper around
pm_runtime_suspended().
If CONFIG_PM=n, cc_pm_is_dev_suspended() a dummy that behaves exactly
the same as the dummy for pm_runtime_suspended().

Hence remove cc_pm_is_dev_suspended(), and call pm_runtime_suspended()
directly.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>