[RISCV] Cleanup setOperationAction calls for INTRINSIC_WO_CHAIN/INTRINSIC_W_CHAIN

We have several extensions that need i32 to be Custom for
INTRINSIC_WO_CHAIN with RV64 so enable it for all RV64.

For V extension, make i32 Custom for RV64 and i64 Custom for RV32.
When the i32 or i64 is legal, the operation action doesn't matter.
LegalizeDAG checks MVT::Other rather than the real type.