restart: replace reset_cpu with registered restart handlers ...

This replaces the reset_cpu() function which every SoC or board must
provide with registered handlers. This makes it possible to have multiple
reset functions for boards which have multiple ways to reset the machine.
Also boards which have no way at all to reset the machine no longer
have to provide a dummy reset_cpu() function.

The problem this solves is that some machines have external PMICs or
similar to reset the system which have to be preferred over the
internal SoC reset, because the PMIC can reset not only the SoC but also
the external devices.

To pick the right way to reset a machine each handler has a priority. The
default priority is 100 and all currently existing restart handlers are
registered with this priority. of_get_restart_priority() allows to retrieve
the priority from the device tree which makes it possible for boards to
give certain restart handlers a higher priority in order to use this one
instead of the default one.

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

ARM: radxa-rock: select options for regulator ...

Fixes the build with a minimal config while maintaining
functionality of the board.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/rockchip' ...

Conflicts:
	arch/arm/Kconfig

ARM: Rockchip: Remove unused files from mach-rockchip ...

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ARM: Rockchip: Add DEBUG_LL based on mach-socfpga ...

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ARM: Rockchip: switch to multiimage support ...

- Add images/Makefile.rockchip
- Allow multiple boards to be selected
- protect initcalls with appropriate of_machine_is_compatible
- rename board specific config to SoC config
- Add dtb file to compilation
- turn barebox_arm_reset_vectorto ENTRY_FUNCTION
- pass dtb to barebox_arm_entry

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

ARM: rockchip: add radxa-rock board ...

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ARM: rockchip: add PLL initialization function ...

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ARM: add basic support for Rockchip SoCs ...

This patch adds a basic support for the ARM-based Rockchip SoCs of the
RK3xxx family.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>