Refine unroll in MIOpenConvBwdWrW_GxL_1x1.cl
Refine unroll in MIOpenConvBwdWrW_GxL_1x1.cl

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