Fix Makefile issue.

Author: quic-zhanweiw

src/CMakeLists.txt

@@ -15,8 +15,6 @@ else()
 set(APP "appbuilder")
 endif()
 
-target_compile_features(${APP} PRIVATE cxx_std_20)
-
 set(APP_SOURCES "QnnSampleApp.cpp"
                 "main.cpp"
                 "Log/Logger.cpp"
@@ -45,6 +43,7 @@ set(APP_SOURCES_ARCH "PAL/src/linux/Directory.cpp"
 endif()
 
 ADD_LIBRARY(${APP} SHARED ${APP_SOURCES} ${APP_SOURCES_ARCH})
+target_compile_features(${APP} PRIVATE cxx_std_20)
 
 if (MSVC)
   target_compile_options(${APP} PRIVATE /O2 /GL /fp:fast)