scripts: imx-image: rename dcdofs to ivtofs ...

This renames the dcdofs config option in the imx-image tool to ivtofs.  dcdofs
is a misnomer. The DCD (Device Configuration Data) is only one part of the data
linked into the IVT (Image Vector Table), but the meaning of the option is
really the latter, not the former.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

regsubst.pl: fix typo in help text ...

It seems I did too much assembler stuff ...

Fixes: e7fed4338441 ("scripts: Provide script that helps using cpp defines in dcd tables")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: Provide script that helps using cpp defines in dcd tables ...

This script was used to help create commit 8f426992c562 ("ARM: imx: use
register defines in imxcfg files instead of plain numbers").

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>