[RISCV] Use ReadJmp for XAndesPerf branch instructions (#230000)
NDSRVInstBB (nds.bbc/nds.bbs) and NDSRVInstBC (nds.beqc/nds.bnec) are
conditional branches, so their register operand should use ReadJmp
rather than ReadIALU, matching the base BranchCC_rri class.