dsg-work-62: GuC doorbell fixes & enable GuC by default

[Dave Gordon]

[PATCH 1/8] drm/i915: Force clean compilation with -Werror
[PATCH 2/8] drm/i915/guc: add enable_guc_loading parameter
[PATCH 3/8] drm/i915/guc: add doorbell map to debugfs/i915_guc_info
[PATCH 4/8] drm/i915/guc: move guc_ring_doorbell() nearer to callsite
[PATCH 5/8] drm/i915/guc: refactor doorbell management code
[PATCH 6/8] drm/i915/guc: (re)initialise doorbell h/w when enabling
[PATCH 7/8] drm/i915/guc: disable GuC submission earlier during GuC
[PATCH 8/8] drm/i915/guc: change default to using GuC submission if

.Dave.