When we detect a error and disable PSR, it is kept disabled until the
next modeset but as the sink already show signs that it do not
properly work with PSR lets disabled it for good to avoid any
additional flickering.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181121225441.18785-3-jose.souza@intel.com