kbuild: use git-archive for source package creation

Commit 5c3d1d0abb ("kbuild: add a tool to list files ignored by git")
added a new tool, scripts/list-gitignored. My intention was to create
source packages without cleaning the source tree, without relying on git.

Linus strongly objected to it, and suggested using 'git archive' instead.
[1] [2] [3]

This commit goes in that direction - Remove scripts/list-gitignored.c
and rewrites Makefiles and scripts to use 'git archive' for building
Debian and RPM source packages. It also makes 'make perf-tar*-src-pkg'
use 'git archive' again.

Going forward, building source packages is only possible in a git-managed
tree. Building binary packages does not require git.

[1]: https://lore.kernel.org/lkml/CAHk-=wi49sMaC7vY1yMagk7eqLK=1jHeHQ=yZ_k45P=xBccnmA@mail.gmail.com/
[2]: https://lore.kernel.org/lkml/CAHk-=wh5AixGsLeT0qH2oZHKq0FLUTbyTw4qY921L=PwYgoGVw@mail.gmail.com/
[3]: https://lore.kernel.org/lkml/CAHk-=wgM-W6Fu==EoAVCabxyX8eYBz9kNC88-tm9ExRQwA79UQ@mail.gmail.com/

Fixes: 5c3d1d0abb ("kbuild: add a tool to list files ignored by git")
Fixes: e0ca16749a ("kbuild: make perf-tar*-src-pkg work without relying on git")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/package/mkspec

@@ -19,6 +19,8 @@ else
 	mkdir -p rpmbuild/SOURCES
 	cp linux.tar.gz rpmbuild/SOURCES
 	cp "${KCONFIG_CONFIG}" rpmbuild/SOURCES/config
+	$(dirname $0)/gen-diff-patch rpmbuild/SOURCES/diff.patch rpmbuild/SOURCES/untracked.patch
+	touch rpmbuild/SOURCES/diff.patch rpmbuild/SOURCES/untracked.patch
 fi
 
 if grep -q CONFIG_MODULES=y include/config/auto.conf; then
@@ -53,6 +55,8 @@ sed -e '/^DEL/d' -e 's/^\t*//' <<EOF
 	URL: https://www.kernel.org
 $S	Source0: linux.tar.gz
 $S	Source1: config
+$S	Source2: diff.patch
+$S	Source3: untracked.patch
 	Provides: $PROVIDES
 $S	BuildRequires: bc binutils bison dwarves
 $S	BuildRequires: (elfutils-libelf-devel or libelf-devel) flex
@@ -90,6 +94,12 @@ $S$M
 $S	%prep
 $S	%setup -q -n linux
 $S	cp %{SOURCE1} .config
+$S	if [ -s %{SOURCE2} ]; then
+$S		patch -p1 < %{SOURCE2}
+$S	fi
+$S	if [ -s %{SOURCE3} ]; then
+$S		patch -p1 < %{SOURCE3}
+$S	fi
 $S
 $S	%build
 $S	$MAKE %{?_smp_mflags} KERNELRELEASE=$KERNELRELEASE KBUILD_BUILD_VERSION=%{release}