ARM: smp: remove wrapper functions

Remove some silly wrapper functions which aren't really required:
	platform_smp_prepare_cpus
	platform_secondary_init
	platform_cpu_die

This simplifies the code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>