[ARM] optimize defterm implementation

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>
[ARM] move SCU symbols to local/static

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>
[ARM] move smp_operation data structure to local/static.

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>