PEL: Pass in subsystem to use with additional data

There is a requirement to pass in the subsystem to use with
the additional data field. In the process update the user
header code and SRC with the passed-in subsystem value
instead from the message registry.

Signed-off-by: Sumit Kumar <sumit_kumar@in.ibm.com>
Change-Id: I08c8c3bab100fec581df9043f4bb27b28cb556e1
diff --git a/extensions/openpower-pels/ascii_string.hpp b/extensions/openpower-pels/ascii_string.hpp
index 0970df9..0fdf124 100644
--- a/extensions/openpower-pels/ascii_string.hpp
+++ b/extensions/openpower-pels/ascii_string.hpp
@@ -72,7 +72,6 @@
      */
     std::string get() const;
 
-  private:
     /**
      * @brief Converts a byte of raw data to 2 characters
      *        and writes it to the offset.
@@ -91,6 +90,7 @@
      */
     void setByte(size_t offset, uint8_t value);
 
+  private:
     /**
      * @brief The ASCII string itself
      */