util/crossgcc: Update gdb to 7.3.1

The previous version is no longer available.

Change-Id: I8126617cfe9addeb4778f002398abbcb4c73d2c7
Signed-off-by: Peter Stuge <peter@stuge.se>
Reviewed-on: http://review.coreboot.org/214
Reviewed-by: Marc Jones <marcj303@gmail.com>
Tested-by: build bot (Jenkins)
diff --git a/util/crossgcc/buildgcc b/util/crossgcc/buildgcc
index 937fb75..6061f26 100755
--- a/util/crossgcc/buildgcc
+++ b/util/crossgcc/buildgcc
@@ -35,7 +35,7 @@
 LIBELF_VERSION=0.8.13
 GCC_VERSION=4.5.2
 BINUTILS_VERSION=2.20.1
-GDB_VERSION=7.2
+GDB_VERSION=7.3.1
 W32API_VERSION=3.17-2
 W32API_VERSION_SHORT=3.17
 MINGWRT_VERSION=3.18