PEL: Rename function that gets RO data path

It was just named after the message registry path, but soon other files
will be in that same directory so make it more generic.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I91117d685aec43f26b9fc6baa2955de3d1affde4
diff --git a/extensions/openpower-pels/paths.cpp b/extensions/openpower-pels/paths.cpp
index cf8df2e..a9e865c 100644
--- a/extensions/openpower-pels/paths.cpp
+++ b/extensions/openpower-pels/paths.cpp
@@ -40,7 +40,7 @@
     return repoPath;
 }
 
-fs::path getMessageRegistryPath()
+fs::path getPELReadOnlyDataPath()
 {
     return std::filesystem::path{"/usr/share/phosphor-logging/pels"};
 }