drm/i915: Move a few utility macros into a separate header

In order to defeat some circular dependencies between headers to allow use
of e.g. range_overflows() in a header, move the simple independent macros
into their own header.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170105153023.30575-4-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7b43662..abc8d73 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -52,6 +52,7 @@
 
 #include "i915_params.h"
 #include "i915_reg.h"
+#include "i915_utils.h"
 
 #include "intel_bios.h"
 #include "intel_dpll_mgr.h"
@@ -219,18 +220,6 @@ static inline const char *enableddisabled(bool v)
 	return v ? "enabled" : "disabled";
 }
 
-#define range_overflows(start, size, max) ({ \
-	typeof(start) start__ = (start); \
-	typeof(size) size__ = (size); \
-	typeof(max) max__ = (max); \
-	(void)(&start__ == &size__); \
-	(void)(&start__ == &max__); \
-	start__ > max__ || size__ > max__ - start__; \
-})
-
-#define range_overflows_t(type, start, size, max) \
-	range_overflows((type)(start), (type)(size), (type)(max))
-
 enum pipe {
 	INVALID_PIPE = -1,
 	PIPE_A = 0,