In preparation to converting Amstrad Delta on-board latches to
basic_mmio_gpio devices, registration of platform devices which depend
on latches and will require initialization of their GPIO pins first,
should be moved out of .machine_init down to late_initcall level, as the
gpio-generic driver is not available until device_initcall time.  The
latch reset operation, which will be replaced with GPIO initialization,
must also be moved to late_initcall for the same reason.

Since there was already another, separate arch_initcall function for
setting up one of those latch dependent devices, the on-board modem
device, reuse that function, i.e., rename it to a name that matches the
new purpose, extend with other device setup relocated from
.machine_init, and move down to the late_initcall level.

While being at it, add missing gpio_free() in case the modem platform
device registration fails.

Thanks to Tony Lindgren <tony@atomide.com> who suggested this approach
instead of shifting up the gpio-generic driver initialization.

In addition, defer registration of the Amstrad Delta ASoC and serio
devices, done from their device driver files, until late_initcall time,
as those drivers will depend on their GPIO pins already requested from
the board late_init() function until updated to register their GPIO pins
themselves.
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>