Because the HDLCD driver acts as a component master it can end
up enabling the runtime PM functionality before the encoders
are initialised. This can cause crashes if the component slave
never probes (missing module) or if the PM operations kick in
before the probe finishes.

Move the enabling of the runtime PM after the component master
has finished collecting the slave components and use the DRM
atomic helpers to suspend and resume the device.
Tested-by: NRobin Murphy <Robin.Murphy@arm.com>
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>

The HDLCD controller is a display controller that supports resolutions
up to 4096x4096 pixels. It is present on various development boards
produced by ARM Ltd and emulated by the latest Fast Models from the
company.

Cc: David Airlie <airlied@linux.ie>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
[Kconfig cleanup and !CONFIG_PM fixes]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>