build: Stop using GALLIUM_STATE_TRACKERS_DIRS for SUBDIRS

configure still uses it to print the enabled state trackers.

Tested-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-and-Tested-by: Andreas Boll <andreas.boll.dev@gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
2 files changed