i915_guc_log_control is GuC interface and GuC APIs that are not user
facing should be named with "intel_guc" prefix hence we change name to
intel_guc_log_control. Also changed the parameter to intel_guc struct.

v2: Move log vma check to intel_guc_log_control (Michal)
    Return -ENODEV when log isn't initialized. (Chris)
Suggested-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/1516808821-3638-4-git-send-email-sagar.a.kamble@intel.com