arm64: dts: stratix10: Use PSCI spin-table for SMP

This reverts commit ba759bf25bc5 ("FogBugz #488851: dts: use
 spin-table for SMP")
U-Boot has implemented PSCI which is preferable to the spin-table
so revert the temporary spin-table changes.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>