eDP spec states that sink device will do a short pulse in HPD
line when there is a PSR/PSR2 error that needs to be handled by
source, this is handling the first and most simples error:
DP_PSR_SINK_INTERNAL_ERROR.

Here taking the safest approach and disabling PSR(at least until
the next modeset), to avoid multiple rendering issues due to
bad pannels.

v5:
added lockdep_assert in psr_disable and renamed psr_disable()
to intel_psr_disable_locked()

v4:
Using CAN_PSR instead of HAS_PSR in intel_psr_short_pulse

v3:
disabling PSR instead of exiting on error
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180626201644.21932-2-jose.souza@intel.com