arm: keystone: remove boilerplate code and use USE_PM_CLK_RUNTIME_OPS

arm: keystone: remove boilerplate code and use USE_PM_CLK_RUNTIME_OPS

USE_PM_CLK_RUNTIME_OPS is introduced so we don't repeat the same code
to do runtime_suspend and runtime_resume across users of PM clocks.
Use it to remove the boilerplate code.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>