ARM: rockchip: decrease the wait time for resume

The register-default delay time for wait the 24MHz OSC stabilization as well
as PMU stabilization is 750ms, let's decrease them to a still safe 30ms.

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>