drm/i915/guc: Move GuC submission declarations into dedicated header

Move GuC submission declarations into dedicated header as we want to
keep uC specific code in separate files.

v2: fix include (Chris)
    update commit message (Joonas)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: MichaĹ Winiarski <michal.winiarski@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171004181343.66348-3-michal.wajdeczko@intel.com
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index e787527..770bac4 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -24,6 +24,7 @@
 
 #include "i915_drv.h"
 #include "intel_uc.h"
+#include "i915_guc_submission.h"
 #include <linux/firmware.h>
 
 /* Reset GuC providing us with fresh state for both GuC and HuC.