build: Add kconfig menu system.

This is an initial commit of the kconfig system.  It is an unmodified
copy from Linux v3.16.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

scripts/kconfig/lxdialog/check-lxdialog.sh

@@ -0,0 +1,87 @@
+#!/bin/sh
+# Check ncurses compatibility
+
+# What library to link
+ldflags()
+{
+	pkg-config --libs ncursesw 2>/dev/null && exit
+	pkg-config --libs ncurses 2>/dev/null && exit
+	for ext in so a dll.a dylib ; do
+		for lib in ncursesw ncurses curses ; do
+			$cc -print-file-name=lib${lib}.${ext} | grep -q /
+			if [ $? -eq 0 ]; then
+				echo "-l${lib}"
+				exit
+			fi
+		done
+	done
+	exit 1
+}
+
+# Where is ncurses.h?
+ccflags()
+{
+	if [ -f /usr/include/ncursesw/curses.h ]; then
+		echo '-I/usr/include/ncursesw -DCURSES_LOC="<curses.h>"'
+		echo ' -DNCURSES_WIDECHAR=1'
+	elif [ -f /usr/include/ncurses/ncurses.h ]; then
+		echo '-I/usr/include/ncurses -DCURSES_LOC="<ncurses.h>"'
+	elif [ -f /usr/include/ncurses/curses.h ]; then
+		echo '-I/usr/include/ncurses -DCURSES_LOC="<curses.h>"'
+	elif [ -f /usr/include/ncurses.h ]; then
+		echo '-DCURSES_LOC="<ncurses.h>"'
+	else
+		echo '-DCURSES_LOC="<curses.h>"'
+	fi
+}
+
+# Temp file, try to clean up after us
+tmp=.lxdialog.tmp
+trap "rm -f $tmp" 0 1 2 3 15
+
+# Check if we can link to ncurses
+check() {
+        $cc -x c - -o $tmp 2>/dev/null <<'EOF'
+#include CURSES_LOC
+main() {}
+EOF
+	if [ $? != 0 ]; then
+	    echo " *** Unable to find the ncurses libraries or the"       1>&2
+	    echo " *** required header files."                            1>&2
+	    echo " *** 'make menuconfig' requires the ncurses libraries." 1>&2
+	    echo " *** "                                                  1>&2
+	    echo " *** Install ncurses (ncurses-devel) and try again."    1>&2
+	    echo " *** "                                                  1>&2
+	    exit 1
+	fi
+}
+
+usage() {
+	printf "Usage: $0 [-check compiler options|-ccflags|-ldflags compiler options]\n"
+}
+
+if [ $# -eq 0 ]; then
+	usage
+	exit 1
+fi
+
+cc=""
+case "$1" in
+	"-check")
+		shift
+		cc="$@"
+		check
+		;;
+	"-ccflags")
+		ccflags
+		;;
+	"-ldflags")
+		shift
+		cc="$@"
+		ldflags
+		;;
+	"*")
+		usage
+		exit 1
+		;;
+esac