openpower-occ-control: use c++17

Update configure.ac to choose the c++17 standard

Change-Id: I4a9a6ef0aa9631da91ffbc83b1d36c838b56cdd4
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/configure.ac b/configure.ac
index 149e0d0..9becfe4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -62,7 +62,7 @@
     AS_IF([test "x$SDBUSPLUSPLUS" == "x"], AC_MSG_ERROR([Cannot find sdbus++]))
 
     # Checks for typedefs, structures, and compiler characteristics.
-    AX_CXX_COMPILE_STDCXX_14([noext])
+    AX_CXX_COMPILE_STDCXX_17([noext])
     AX_APPEND_COMPILE_FLAGS([-Wall -Werror], [CXXFLAGS])
 
     AC_ARG_ENABLE([i2c-occ],