scripts: socfpga sequencer extraction tool ...

This script extracts the socfpga sequencer from a generated u-boot
automagically. The resulting changes of the barebox tree should be
enough to compile with the new sequencer.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>