drm/i915: Use new i915_gem_object_pin_map for LRC

We can use the new pin/lazy unpin API for simplicity
and more performance in the execlist submission paths.

v2:
  * Fix error handling and convert more users.
  * Compact some names for readability.

v3:
  * intel_lr_context_free was not unpinning.
  * Special case for GPU reset which otherwise unbalances
    the HWS object pages pin count by running the engine
    initialization only (not destructors).

v4:
  * Rebased on top of hws setup/init split.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1460472042-1998-1-git-send-email-tvrtko.ursulin@linux.intel.com
[tursulin: renames: s/hwd/hws/, s/obj_addr/vaddr/]
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index fe580cb..91028d9 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -342,7 +342,7 @@
 		struct intel_context *ctx;
 
 		list_for_each_entry(ctx, &dev_priv->context_list, link)
-			intel_lr_context_reset(dev, ctx);
+			intel_lr_context_reset(dev_priv, ctx);
 	}
 
 	for (i = 0; i < I915_NUM_ENGINES; i++) {