What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind task

What does this PR do / why do we need it:
GPU implementation of SoftMarginLoss, SoftMarginLossGrad

Which issue(s) this PR fixes:

Fixes
#I4ZZUU:【众智】【计算-GPU开发】SoftMarginLoss
#I4ZZUV:【众智】【计算-GPU开发】SoftMarginLossGrad

Special notes for your reviewers: