mpi: update MPI_VERSION/MPI_SUBVERSION to 5.0

Prepare for the support of upcoming MPI 5.0 standard. Update the
versions facilitates down stream testing.

NOTE: revert if the Forum couldn't make it by November.

Author: hzhou

CHANGES

@@ -1,6 +1,8 @@
 ===============================================================================
                                Changes in 5.0
 ===============================================================================
+# MPI_VERSION/MPI_SUBVERSION updated to 5 and 0.
+
 # MPIR_CHKLMEM_ and MPIR_CHKPMEM_ macros are simplified, removing non-essential
   argument such as type case and custom error messages.
 

src/include/mpi.h.in

@@ -35,11 +35,11 @@
 #endif
 
 #ifndef BUILD_MPI_ABI
-#define MPI_VERSION    4
-#define MPI_SUBVERSION 1
+#define MPI_VERSION    5
+#define MPI_SUBVERSION 0
 #endif /* BUILD_MPI_ABI */
 
-#define MPICH_NAME     4
+#define MPICH_NAME     5
 #define MPICH         1
 #define MPICH_HAS_C2F  1