* fix multhead matmul's instable
test=develop

* fix multihead matmul bug
test=develop

* fix converage problem
test=develop
Co-authored-by: NZhaolong Xing <nhzlx.dragon@gmail.com>

* 1. optim multihead matmul: fuse three fc to multihtead matmul

test=develop

* fix conflict
test=develop

* fix comments
test=develop

* Add multihead fuse pass for ernie opt

* Refine softmax

test=develop

* Refine cuda kernel

* Refine cuda version

* Refine cmake

test=develop

* refine header file

* refine test case and pass
* refine comments