gpu: nvgpu: Add doxygen safety profile build

Add a doxygen build to nvgpu. Use the following command from the
drivers/gpu/nvgpu directory:

  $ make -f Makefile.doxygen

This will autogenerate a list of files from the safety profile
architecture and then generate doxygen documentation from said
list of files.

Also add a .gitignore entry for the sources file that gets
generated during the build.

JIRA NVGPU-3544

Change-Id: I2415de631efcc8447c81ace1700ebac8b69a89df
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2131051
Reviewed-by: Seema Khowala <seemaj@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

.gitignore

@@ -96,3 +96,6 @@ x509.genkey
 
 # Kconfig presets
 all.config
+
+# Source files we generate from arch for doxygen.
+Doxyfile.sources.safety

drivers/gpu/nvgpu/Makefile.doxygen

@@ -0,0 +1,44 @@
+##################### tell Emacs this is a -*- makefile-gmake -*-
+#
+# Copyright (c) 2019 NVIDIA CORPORATION.  All Rights Reserved.
+#
+# NVIDIA CORPORATION and its licensors retain all intellectual property
+# and proprietary rights in and to this software, related documentation
+# and any modifications thereto.  Any use, reproduction, disclosure or
+# distribution of this software and related documentation without an express
+# license agreement from NVIDIA CORPORATION is strictly prohibited.
+#
+# Build the doxygen output.
+#
+# Some assumptions: this is a local build only. You need installed:
+#
+#   doxygen
+#   python2
+#
+# You also must have $TOP/$TEGRA_TOP set; For L4T:
+#
+#   $ export TOP=$TEGRA_TOP
+#
+# Should work.
+#
+
+PYTHON2    = python2.7
+ARCH       = $(TEGRA_TOP)/core-private/tools/arch/arch.py
+NVGPU_ARCH = $(TOP)/kernel/nvgpu/arch
+ARCH_YAML  = $(NVGPU_ARCH)/*.yaml
+
+# Build the doxygen output. But make sure the sources file is generated
+# first.
+all: doxygen/sources
+	doxygen doxygen/Doxyfile.safety
+
+# Generate the sources file. This has a list of files that we shall include
+# in the doxygen output.
+doxygen/sources: $(ARCH) $(ARCH_YAML)
+	$(ARCH) --arch-file $(NVGPU_ARCH)/nvgpu.yaml files	\
+		--safe --gpu igpu --gpu both			\
+		--prefix 'INPUT += ' > doxygen/Doxyfile.sources.safety
+
+clean:
+	rm -rf doxygen/Doxyfile.sources.safety
+	rm -rf html