Dwarf support does not compile on Blackfin

Reported upstream:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68468

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>

diff -Nur gcc-6.1.0.orig/libgcc/config.host gcc-6.1.0/libgcc/config.host
--- gcc-6.1.0.orig/libgcc/config.host	2016-02-26 21:02:28.000000000 +0100
+++ gcc-6.1.0/libgcc/config.host	2016-05-12 19:26:30.973350274 +0200
@@ -230,6 +230,13 @@
       ;;
   esac
   ;;
+bfin-*-*linux*)
+  tmake_file="$tmake_file t-crtstuff-pic t-libgcc-pic t-slibgcc t-slibgcc-gld t-slibgcc-elf-ver t-linux"
+  extra_parts="crtbegin.o crtbeginS.o crtbeginT.o crtend.o crtendS.o"
+  if test x$enable_vtable_verify = xyes; then
+    extra_parts="$extra_parts vtv_start.o vtv_end.o vtv_start_preinit.o vtv_end_preinit.o"
+  fi
+  ;;
 *-*-linux* | frv-*-*linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu | *-*-gnu* | *-*-kopensolaris*-gnu)
   tmake_file="$tmake_file t-crtstuff-pic t-libgcc-pic t-eh-dw2-dip t-slibgcc t-slibgcc-gld t-slibgcc-elf-ver t-linux"
   extra_parts="crtbegin.o crtbeginS.o crtbeginT.o crtend.o crtendS.o"