drm/i915: Add wrapper for getting display step

Add a wrapper around intel_step_name that takes in driver data as an
argument. This wrapper will help maintain compatibility with the
proposed xe driver.
Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231003065211.1052385-1-chaitanya.kumar.borah@intel.com

drivers/gpu/drm/i915/display/intel_dmc.c

@@ -309,7 +309,7 @@ static const struct stepping_info *
 intel_get_stepping_info(struct drm_i915_private *i915,
 			struct stepping_info *si)
 {
-	const char *step_name = intel_step_name(RUNTIME_INFO(i915)->step.display_step);
+	const char *step_name = intel_display_step_name(i915);
 
 	si->stepping = step_name[0];
 	si->substepping = step_name[1];

drivers/gpu/drm/i915/intel_step.c

@@ -353,3 +353,8 @@ const char *intel_step_name(enum intel_step step)
 		return "**";
 	}
 }
+
+const char *intel_display_step_name(struct drm_i915_private *i915)
+{
+	return intel_step_name(RUNTIME_INFO(i915)->step.display_step);
+}

drivers/gpu/drm/i915/intel_step.h

@@ -78,5 +78,6 @@ enum intel_step {
 
 void intel_step_init(struct drm_i915_private *i915);
 const char *intel_step_name(enum intel_step step);
+const char *intel_display_step_name(struct drm_i915_private *i915);
 
 #endif /* __INTEL_STEP_H__ */