Almost each SMP platform defines pen_release to manage booting secondary
CPUs. This of course clashes with the single zImage effort.

Add the pen_release definition to the ARM SMP code, and remove all others.
This should only be used by platforms which lack any kind of CPU power
management...
Reported-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>