[RISCV][SelectionDAG] Enable TargetLowering::hasBitTest for masks that fit in ANDI.

Modified DAGCombiner to pass the shift the bittest input and the shift amount
to hasBitTest. This matches the other call to hasBitTest in TargetLowering.h

This is an alternative to D122454.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D122458