drm/i915: Convert i915_perf to ww locking as well

drm/i915: Convert i915_perf to ww locking as well

We have the ordering of timeline->mutex vs resv_lock wrong,
convert the i915_pin_vma and intel_context_pin as well to
future-proof this.

We may need to do future changes to do this more transaction-like,
and only get down to a single i915_gem_ww_ctx, but for now this
should work.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-18-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>