IBM Z: zTPF: Include glibc-stdint.h to get __UINTPTR_TYPE__ defined

Building a zTPF cross currently fails when building libstdc++
complaining about the __UINTPTR_TYPE__ to be missing.

Fixed by including the glibc-stdint.h header.

2020-03-04  Andreas Krebbel  <krebbel@linux.ibm.com>

	* config.gcc: Include the glibc-stdint.h header for zTPF.

gcc/config.gcc

@@ -3104,7 +3104,7 @@ s390x-*-linux*)
 	tmake_file="${tmake_file} s390/t-linux64 s390/t-s390"
 	;;
 s390x-ibm-tpf*)
-	tm_file="s390/s390x.h s390/s390.h dbxelf.h elfos.h s390/tpf.h"
+	tm_file="s390/s390x.h s390/s390.h dbxelf.h elfos.h glibc-stdint.h s390/tpf.h"
 	tm_p_file=s390/s390-protos.h
 	c_target_objs="${c_target_objs} s390-c.o"
 	cxx_target_objs="${cxx_target_objs} s390-c.o"