docs: fix doxygen build error

refs: #4815

Change-Id: Ic5329515615732d7e243799e4ad5e8a1c81a1181
diff --git a/docs/doxygen.conf.in b/docs/doxygen.conf.in
index 44453eb..bcde9c6 100644
--- a/docs/doxygen.conf.in
+++ b/docs/doxygen.conf.in
@@ -780,7 +780,7 @@
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = src
+INPUT                  = PSync
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -2031,7 +2031,7 @@
 # preprocessor.
 # This tag requires that the tag SEARCH_INCLUDES is set to YES.
 
-INCLUDE_PATH           =
+INCLUDE_PATH           = ..
 
 # You can use the INCLUDE_FILE_PATTERNS tag to specify one or more wildcard
 # patterns (like *.h and *.hpp) to filter out the header-files in the