drm/v3d: Get rid of pm code

drm/v3d: Get rid of pm code

Runtime PM doesn't seem to work correctly on this driver. On top of
that, commit c064cdba7d81 ("drm/v3d/v3d_drv: Remove unused static
variable 'v3d_v3d_pm_ops'") hints that it most likely never did as the
driver's PM ops were not hooked-up.

So, in order to support regular operation with V3D on BCM2711 (Raspberry
Pi 4), get rid of the PM code. PM will be reinstated once we figure out
the underlying issues.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220603092610.1909675-3-pbrobinson@gmail.com