Revert "kernel: Remove CONFIG_KSU_MANUAL_SU protection"

This reverts commit fa229b23a4.

kernel/supercalls.c

@@ -20,7 +20,10 @@
 #include "kernel_compat.h"
 #include "throne_comm.h"
 #include "dynamic_manager.h"
+
+#ifdef CONFIG_KSU_MANUAL_SU
 #include "manual_su.h"
+#endif
 
 // Forward declarations from core_hook.c
 extern void escape_to_root(void);