buildgcc: Update and fix GDB

GDB stopped building ever since we updated from version 7.6
but nobody noticed ;)
Update from 7.9 to 7.9.1 and bring the required patches forward.

Change-Id: I2f357525a46d5540e9f57b80d830943bbd5dfcaf
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: http://review.coreboot.org/10494
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <edward.ocallaghan@koparo.com>
diff --git a/util/crossgcc/patches/gdb-7.9.1_no-doc.patch b/util/crossgcc/patches/gdb-7.9.1_no-doc.patch
new file mode 100644
index 0000000..156337a
--- /dev/null
+++ b/util/crossgcc/patches/gdb-7.9.1_no-doc.patch
@@ -0,0 +1,12 @@
+diff -ur gdb-7.9.1/gdb/Makefile.in gdb-7.9.1/gdb/Makefile.in
+--- gdb-7.9.1/gdb/Makefile.in	2015-05-13 10:36:05.000000000 -0700
++++ gdb-7.9.1/gdb/Makefile.in	2015-06-09 13:22:53.594505278 -0700
+@@ -1065,7 +1065,7 @@
+ 
+ TSOBS = inflow.o
+ 
+-SUBDIRS = doc @subdirs@ data-directory $(GNULIB_BUILDDIR)
++SUBDIRS = @subdirs@ data-directory $(GNULIB_BUILDDIR)
+ CLEANDIRS = $(SUBDIRS)
+ 
+ # List of subdirectories in the build tree that must exist.