anv: force StackIDControl value for Wa_14021821874
What does this MR do and why?
anv: force StackIDControl value for Wa_14021821874
This is also encouraged by another wa, Wa_14018813551.
Both workarounds state that StackIDControlOverride_RTGlobals should
always be set to 0 (i.e. 2k).
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>