treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

console_countdown: Add pattern list ...

This adds an optional string argument to console_countdown() which can
hold a list of keys which also abort the countdown.

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

console_countdown: ignore errors in getchar() ...

The getchar() call may return an error reported as a -1, e.g. when the
console detects a RATP message and switches to RATP mode.

In general it probably is a good idea to ignore these errors in the
console countdown operation; and in particular for the RATP usecase,
this also prevents from interfering with the countdown and menu just
when switching one of the consoles to RATP mode.

As a hint, this is what the standard console was printing due to this
issue when the RATP console was activated:

   Hit m for menu or any other key to stop autoboot: [: missing `]'

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

console_countdown: add possibility to abort countdown by external commands ...

This patch makes it possible to abort a console countdown by an external
command, for example when fastboot is used. This requires additional
modifications in the external commands, a call to "console_countdown_abort()"
has to be inserted.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

console_countdown: width to of countdown to 4 digits ...

This patch increases the displayed width of the countdown to 4 digits,
otherwise waiting for more then 99 seconds doesn't look good.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

stdio: rename getc to getchar ...

The function we have implemented as getc has the semantics of the
standard function getchar, so rename it accorgingly.

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

timeout: factor out wait-for-key-press loop into separate file ...

This patch factors out the wait-for-key-press loop from the shell command
"timeout" into a sparate file, so that it can be used from C, too.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>