ipa: raspberrypi: Change to C style code comments

As part of the on-going refactor efforts for the source files in
src/ipa/raspberrypi/, switch all C++ style comments to C style comments.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/ipa/raspberrypi/controller/contrast_status.h

@@ -6,8 +6,10 @@
  */
 #pragma once
 
-// The "contrast" algorithm creates a gamma curve, optionally doing a little bit
-// of contrast stretching based on the AGC histogram.
+/*
+ * The "contrast" algorithm creates a gamma curve, optionally doing a little bit
+ * of contrast stretching based on the AGC histogram.
+ */
 
 #ifdef __cplusplus
 extern "C" {