Now that we can rely on the enable-method, remove the smp field declaration
from A31 machine.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

CPU_METHOD_OF_DECLARE allows to bind the smp_ops to a set of cpus through the
enable-method property, instead of relying on the machine to define it. Switch
to it to get closer to an empty machine.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Building an SMP kernel for the sunxi platform with THUMB2 instructions
fails with this error at the moment:

headsmp.S:7: Error: Thumb encoding does not support an immediate here -- `msr cpsr_fsxc,#0xd3'

Since the generic secondary_startup function already does
the same thing in a safe way, we can just drop the private
sunxi implementation and jump straight to secondary_startup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>

The A31 is a quad Cortex-A7. Add the logic to use the IPs used to
control the CPU configuration and the CPU power so that we can bring up
secondary CPUs at boot.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>