[OpenMP][libomptarget] Add new version of SPMD deinit kernel function with argument

Summary: To enable the compiler to optimize parts of the function that are not needed when runtime can be omitted, a new version of the SPMD deinit kernel function is needed. This function takes the runtime required flag as an argument.

Reviewers: ABataev, kkwli0, caomhin

Reviewed By: ABataev

Subscribers: guansong, openmp-commits

Differential Revision: https://reviews.llvm.org/D54969

llvm-svn: 347714