nyx: bpmp: automatically find best clock for t210

There were 4 reports of Nyx hanging or UMS and backup verification failing because of low binned Erista SoC.

This change reduces clock for hekate main and Nyx will now automatically try and find a working one.
In case Nyx hangs it will reduce it on next inject.

If Nyx works and user still has issues with UMS/Verification, manually editing nyx.ini and setting `bpmpclock=2` will fix that.

bootloader/config.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020 CTCaer
+ * Copyright (c) 2018-2021 CTCaer
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -58,7 +58,7 @@ int create_config_entry()
 	if (!sd_mount())
 		return 1;
 
-	char lbuf[32];
+	char lbuf[64];
 	FIL fp;
 	bool mainIniFound = false;