sun7i: Move psci_arch_init close to text_end

"adr rX, text_end" only works if the label is close. Adding further code
to the other functions will prevent this. So move the containing
function close to label. No functional change.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>