Add MIOPEN_DEBUG_CONV_GEMM env var. (#1349)
Add MIOPEN_DEBUG_CONV_GEMM env var. (#1349)

* conv-gemm-env-var(1) Added MIOPEN_DEBUG_CONV_GEMM var, used for conv except group and depthwise.

* conv-gemm-env-var(2) Fix warnings

ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen