kernel: delete separate logic for priv stacks

This never needed to be put in a separate gperf table.
Privilege mode stacks can be generated by the main
gen_kobject_list.py logic, which we do here.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
diff --git a/kernel/include/kernel_internal.h b/kernel/include/kernel_internal.h
index 15f6d4a..c1fd0e2 100644
--- a/kernel/include/kernel_internal.h
+++ b/kernel/include/kernel_internal.h
@@ -124,6 +124,10 @@
 extern K_THREAD_STACK_ARRAY_DEFINE(z_interrupt_stacks, CONFIG_MP_NUM_CPUS,
 				   CONFIG_ISR_STACK_SIZE);
 
+#ifdef CONFIG_GEN_PRIV_STACKS
+extern u8_t *z_priv_stack_find(k_thread_stack_t *stack);
+#endif
+
 #ifdef __cplusplus
 }
 #endif