ARM: actions: remove boot_lock and pen_release

The actions SMP implementation has several issues:

1. pen_release is only ever read and compared to -1, and is defined in
   arch/arm/kernel/smp.c to be -1.  This test will always succeed.

2. we are already guaranteed to be single threaded while bringing up a
   CPU, so the spinlock makes no sense, remove it.

3. owl_secondary_startup() is not referenced nor defined, the prototype
   is redundant, remove it.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>