mesa: fix incomplete GL_NV_half_float implementation
All of the VertexAttrib* functions were missing.
Fixes: ef66e02a ("src/mesa: add GL_NV_half_float extension support (v2)")
All of the VertexAttrib* functions were missing.
Fixes: ef66e02a ("src/mesa: add GL_NV_half_float extension support (v2)")