Add sceKernelGetThreadId to threadmgr.h
Add sceKernelGetThreadId to threadmgr.h

173210/psp2sdk,psp2sdk/cmake,psp2sdk/cmake,psp2sdk/cmake,173210/psp2sdk_travis,173210/psp2sdk,173210/psp2sdk_travis,173210/psp2sdk_travis,173210/psp2sdk