arm: dts: socfpga: arria10: Move to use generic handoff dtsi

Move to use generic handoff dtsi (socfpga_arria10-handoff.dtsi) and include
the specify generated _handoff.h header file from qts-filter-a10.sh script.

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>