drm/i915/guc: Decouple GuC engine id from ring id

Previously GuC uses ring id as engine id because of same definition.
But this is not true since this commit:

commit de1add360522c876c25ef2bbbbab1c94bdb509ab
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Fri Jan 15 15:12:50 2016 +0000

    drm/i915: Decouple execbuf uAPI from internal implementation

Added GuC engine id into GuC interface to decouple it from ring id used
by driver.

v2: Keep ring name print out in debugfs; using for_each_ring() where
    possible to keep driver consistent. (Chris W.)

Signed-off-by: Alex Dai <yu.dai@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453579094-29860-1-git-send-email-yu.dai@intel.com
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index 045b149..73002e9 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -46,7 +46,7 @@
 	uint32_t wq_head;
 
 	/* GuC submission statistics & status */
-	uint64_t submissions[I915_NUM_RINGS];
+	uint64_t submissions[GUC_MAX_ENGINES_NUM];
 	uint32_t q_fail;
 	uint32_t b_fail;
 	int retcode;
@@ -106,8 +106,8 @@
 	uint32_t action_fail;		/* Total number of failures	*/
 	int32_t action_err;		/* Last error code		*/
 
-	uint64_t submissions[I915_NUM_RINGS];
-	uint32_t last_seqno[I915_NUM_RINGS];
+	uint64_t submissions[GUC_MAX_ENGINES_NUM];
+	uint32_t last_seqno[GUC_MAX_ENGINES_NUM];
 };
 
 /* intel_guc_loader.c */