bug fixes for universal intrinsics of RISC-V back-end
* Align universal intrinsic comparator behaviour with other platforms
Set all bits to one for return value of int and fp comparators.
* fix v_pack_triplets, v_pack_store and v_pack_u_store
* Remove redundant CV_DECL_ALIGNED statements
Co-authored-by: Alexander Smorkalov <alexander.smorkalov@xperience.ai>