drm/i915: Dial down workaround debug messages

For selftests like live_hangcheck, which does thousands of reset per
second, it is too verbose to log every time we re-apply the workarounds.

Remove those messages since, coupled with the dedicated selftest, it is
sufficient to only log the number of recorded workarounds at init time.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181204171530.28583-1-tvrtko.ursulin@linux.intel.com