[Stock] Add cleaner stock

[Stock]
fss0={sd path}
stock=1

Can now work for both older and new HOS versions.

- <= 6.2.0 loads nothing and removes kernel patching.
- >= 7.0.0 loads exo, wb and removes kernel patching.

This requires that fss0 {sd path} is valid. Otherwise it will fail on ini cfg parsing.

If <= 6.2.0 and no FSS0
[Stock]
stock=1

will provide a cleaner stock with no kernel patching.

bootloader/hos/hos_config.h

@@ -19,7 +19,7 @@
 
 #include "hos.h"
 
-int parse_boot_config(launch_ctxt_t *ctxt, ini_sec_t *cfg);
+int parse_boot_config(launch_ctxt_t *ctxt);
 int config_kip1patch(launch_ctxt_t *ctxt, const char *value);
 
 #endif