nir: fix missing nir_lower_pntc_ytransform.c in the makefile

Fixes: 33fd9e5d "nir: account for point-coord origin when lowering it"
Signed-off-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Part-of: <!8308>
91 jobs for !8308 with fix/nir_lower_pntc_ytransform-include in 16 minutes and 29 seconds (queued for 6 seconds)
merge request