dmaengine: pl330: Drop boilerplate code for suspend/resume

dmaengine: pl330: Drop boilerplate code for suspend/resume

Let's drop the boilerplate code in the system suspend/resume callbacks and
convert to use pm_runtime_force_suspend|resume(). This change also has a
nice side effect, as pm_runtime_force_resume() may decide to leave the
device in low power state, when that is feasible, thus avoiding to waste
both time and energy during system resume.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20191205143746.24873-2-ulf.hansson@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>