intel/genxml: Add genX_rt_pack.h
Extend @llandwerlin's 7d7c32de a bit to add genX_rt_pack.h. It can eventually be used for multiple gens, similar to genX_pack.h.
Extend @llandwerlin's 7d7c32de a bit to add genX_rt_pack.h. It can eventually be used for multiple gens, similar to genX_pack.h.