Add riscv64 support for apex prebuilt

This add support for src field in bp file.

Signed-off-by: Chen Guoyin <chenguoyin.cgy@linux.alibaba.com>
Signed-off-by: Mao Han <han_mao@linux.alibaba.com>
Change-Id: I9393696951db375d53436f9d5a9841b6a072cea3