[RISCV] Refactor predicates for rvv intrinsic patterns.

This patch does the following things:

1, Add accurate Predicates in intrinsic-pseudo pattern class depending on the vector type.
2, Make vmulh, vmulhsu, vmulhu and vsmul intrinsic only able to select in v extension.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D150550