msm: kgsl: rework ib checking

Separate ib parse checking from cffdump as it is usefulin other situations. This is controlled by a new debugfsfile, ib_check. All ib checking is off (0) by default,because parsing and mem_entry lookup can have a performanceimpact on some benchmarks. Level 1 checking verifies theIB1's. Level 2 checking also verifies the IB2.