tegra: add new target

New target introduces initial support for NVIDIA Tegra SoC based devices.
It focuses on Tegra 2 CPUs, for successors supporting NEON instruction
set the target should be split in two subtargets.
This initial commit doesn't create any device image, it's groundwork
for further additions.

Signed-off-by: Tomasz Maciej Nowak <tomek_n@o2.pl>

target/linux/tegra/base-files/lib/preinit/79_move_config

@@ -0,0 +1,22 @@
+#!/bin/sh
+
+move_config() {
+	local partdev
+
+	. /lib/upgrade/common.sh
+
+	if export_bootdevice && export_partdevice partdev 1; then
+		mkdir -p /boot
+		if mount -o ro,noatime "/dev/$partdev" /boot; then
+			if [ -f /boot/sysupgrade.tgz ]; then
+				mount /boot -o remount,rw,noatime
+				mv -f /boot/sysupgrade.tgz /
+			fi
+			umount /boot
+			rm -fR /boot
+		fi
+	fi
+}
+
+boot_hook_add preinit_mount_root move_config
+