Revert "drm/i915: Enable PSR by default."

This reverts commit b6d54779.

The panel self refresh clearly isn't stable yet, and causes my laptop
(Haswell ULT in a Sony Vaio Pro) to have the screen lock up.  Maybe it
doesn't ever get out of self-refresh, or maybe there are gremlins in the
machine that get unhappy.  Regardless, it's broken, and it gets
reverted.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/i915/i915_params.c

@@ -37,7 +37,7 @@ struct i915_params i915 __read_mostly = {
 	.enable_fbc = -1,
 	.enable_hangcheck = true,
 	.enable_ppgtt = -1,
-	.enable_psr = 1,
+	.enable_psr = 0,
 	.preliminary_hw_support = IS_ENABLED(CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT),
 	.disable_power_well = 1,
 	.enable_ips = 1,
@@ -119,7 +119,7 @@ MODULE_PARM_DESC(enable_ppgtt,
 	"(-1=auto [default], 0=disabled, 1=aliasing, 2=full)");
 
 module_param_named(enable_psr, i915.enable_psr, int, 0600);
-MODULE_PARM_DESC(enable_psr, "Enable PSR (default: true)");
+MODULE_PARM_DESC(enable_psr, "Enable PSR (default: false)");
 
 module_param_named(preliminary_hw_support, i915.preliminary_hw_support, int, 0600);
 MODULE_PARM_DESC(preliminary_hw_support,