pipeline: ipa: raspberrypi: Refactor and move the Raspberry Pi code

Split the Raspberry Pi pipeline handler and IPA source code into common
and VC4/BCM2835 specific file structures.

For the pipeline handler, the common code files now live in
src/libcamera/pipeline/rpi/common/
and the VC4-specific files in src/libcamera/pipeline/rpi/vc4/.

For the IPA, the common code files now live in
src/ipa/rpi/{cam_helper,controller}/
and the vc4 specific files in src/ipa/rpi/vc4/. With this change, the
camera tuning files are now installed under share/libcamera/ipa/rpi/vc4/.

To build the pipeline and IPA, the meson configuration options have now
changed from "raspberrypi" to "rpi/vc4":

meson setup build -Dipas=rpi/vc4 -Dpipelines=rpi/vc4

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

src/ipa/rpi/controller/denoise_algorithm.h

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2021, Raspberry Pi Ltd
+ *
+ * denoise.h - Denoise control algorithm interface
+ */
+#pragma once
+
+#include "algorithm.h"
+
+namespace RPiController {
+
+enum class DenoiseMode { Off, ColourOff, ColourFast, ColourHighQuality };
+
+class DenoiseAlgorithm : public Algorithm
+{
+public:
+	DenoiseAlgorithm(Controller *controller) : Algorithm(controller) {}
+	/* A Denoise algorithm must provide the following: */
+	virtual void setMode(DenoiseMode mode) = 0;
+};
+
+} /* namespace RPiController */