target-mips: Set Config5.XNP for R6 cores Set Config5.XNP for R6 cores to indicate the extended LL/SC family of instructions NOT present. Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com> Reviewed-by: Leon Alrae <leon.alrae@imgtec.com> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>