util/kconfig: Uprev to Linux 5.13's kconfig

This was originally several commits that had to be squashed into one
because the intermediate states weren't able to build coreboot:

 - one to remove everything that wasn't our own code, leaving only
   regex.[ch], toada.c, description.md and Makefile.inc.
 - one to copy in Linux 5.13's scripts/kconfig and adapt Makefile.inc
   to make the original Makefile work again.
 - adapt abuild to use olddefconfig, simplifying matters.
 - apply patches in util/kconfig/patches.
 - Some more adaptations to the libpayload build system.

The patches are now in util/kconfig/patches/, reverse applying them
should lead to a util/kconfig/ tree that contains exactly the Linux
version + our own 5 files.

Change-Id: Ia0e8fe4e9022b278f34ab113a433ef4d45e5c355
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37152
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

util/kconfig/mconf-cfg.sh

@@ -0,0 +1,52 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+PKG="ncursesw"
+PKG2="ncurses"
+
+if [ -n "$(command -v pkg-config)" ]; then
+	if pkg-config --exists $PKG; then
+		echo cflags=\"$(pkg-config --cflags $PKG)\"
+		echo libs=\"$(pkg-config --libs $PKG)\"
+		exit 0
+	fi
+
+	if pkg-config --exists $PKG2; then
+		echo cflags=\"$(pkg-config --cflags $PKG2)\"
+		echo libs=\"$(pkg-config --libs $PKG2)\"
+		exit 0
+	fi
+fi
+
+# Check the default paths in case pkg-config is not installed.
+# (Even if it is installed, some distributions such as openSUSE cannot
+# find ncurses by pkg-config.)
+if [ -f /usr/include/ncursesw/ncurses.h ]; then
+	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncursesw\"
+	echo libs=\"-lncursesw\"
+	exit 0
+fi
+
+if [ -f /usr/include/ncurses/ncurses.h ]; then
+	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncurses\"
+	echo libs=\"-lncurses\"
+	exit 0
+fi
+
+# As a final fallback before giving up, check if $HOSTCC knows of a default
+# ncurses installation (e.g. from a vendor-specific sysroot).
+if echo '#include <ncurses.h>' | ${HOSTCC} -E - >/dev/null 2>&1; then
+	echo cflags=\"-D_GNU_SOURCE\"
+	echo libs=\"-lncurses\"
+	exit 0
+fi
+
+echo >&2 "*"
+echo >&2 "* Unable to find the ncurses package."
+echo >&2 "* Install ncurses (ncurses-devel or libncurses-dev"
+echo >&2 "* depending on your distribution)."
+echo >&2 "*"
+echo >&2 "* You may also need to install pkg-config to find the"
+echo >&2 "* ncurses installed in a non-default location."
+echo >&2 "*"
+exit 1