drm/i915: init per-engine WAs for all engines

commit 4a15c75c ("drm/i915: Introduce per-engine workarounds")
refactored the workaround code to have functions per-engine, but didn't
call any of them from logical_xcs_ring_init. Since we do have a non-RCS
workaround for KBL (WaKBLVECSSemaphoreWaitPoll) we do need to call
intel_engine_init_workarounds for non-RCS engines.
Note that whitelist is still RCS-only.

v2: move the call to logical_ring_init (Chris)

Fixes: 4a15c75c

 ("drm/i915: Introduce per-engine workarounds")
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190110013232.8972-2-daniele.ceraolospurio@intel.com