drm/tidss: Use PM autosuspend

Use runtime PM autosuspend feature, with 1s timeout, to avoid
unnecessary suspend-resume cycles when, e.g. the userspace temporarily
turns off the crtcs when configuring the outputs.

Reviewed-by: Aradhya Bhatia <a-bhatia1@ti.com>
Link: https://lore.kernel.org/r/20231109-tidss-probe-v2-2-ac91b5ea35c0@ideasonboard.com


Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>