Fix spelling error in generated helper code

Also a minor comment fix in the generator script.

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>

scripts/generate_ssl_debug_helpers.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-"""Generate library/ssl_debug_helps_generated.c
+"""Generate library/ssl_debug_helpers_generated.c
 
 The code generated by this module includes debug helper functions that can not be
 implemented by fixed codes.
@@ -224,7 +224,7 @@ class EnumDefinition:
                 if( in > ( sizeof( in_to_str )/sizeof( in_to_str[0]) - 1 ) ||
                     in_to_str[ in ] == NULL )
                 {{
-                    return "UNKOWN_VAULE";
+                    return "UNKNOWN_VALUE";
                 }}
                 return in_to_str[ in ];
             }}