ARM: sirf: move platsmp to support Atlas7 SoC

This patch breaks Marco SMP support, but Marco project has been dropped.
So it corrects cpu1 jump/flag address for Atlas7 and removes scu related
logic as scu doesn't expose in cortex-a7.

Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>