fbdev: omapfb/dss: Use pm_runtime_resume_and_get() instead of pm_runtime_get_sync()

Using the newest pm_runtime_resume_and_get is more appropriate
for simplifing code here.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Helge Deller <deller@gmx.de>