ipa: libipa: Convert to pragma once

Remove the verbose #ifndef/#define/#endif pattern for maintaining
header idempotency, and replace it with a simple #pragma once.

This simplifies the headers, and prevents redundant changes when
header files get moved.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>

src/ipa/libipa/camera_sensor_helper.h

@@ -4,8 +4,8 @@
  *
  * camera_sensor_helper.h - Helper class that performs sensor-specific parameter computations
  */
-#ifndef __LIBCAMERA_IPA_LIBIPA_CAMERA_SENSOR_HELPER_H__
-#define __LIBCAMERA_IPA_LIBIPA_CAMERA_SENSOR_HELPER_H__
+
+#pragma once
 
 #include <stdint.h>
 
@@ -85,5 +85,3 @@ static helper##Factory global_##helper##Factory;
 } /* namespace ipa */
 
 } /* namespace libcamera */
-
-#endif /* __LIBCAMERA_IPA_LIBIPA_CAMERA_SENSOR_HELPER_H__ */

src/ipa/libipa/histogram.h

@@ -4,8 +4,8 @@
  *
  * histogram.h - histogram calculation interface
  */
-#ifndef __LIBCAMERA_IPA_LIBIPA_HISTOGRAM_H__
-#define __LIBCAMERA_IPA_LIBIPA_HISTOGRAM_H__
+
+#pragma once
 
 #include <assert.h>
 #include <limits.h>
@@ -36,5 +36,3 @@ private:
 } /* namespace ipa */
 
 } /* namespace libcamera */
-
-#endif /* __LIBCAMERA_IPA_LIBIPA_HISTOGRAM_H__ */