Update coreboot cross toolchain to gcc 4.6.1

- Tested on Mac OS X 10.7.1
- Tested on Ubuntu 10.04 LTS (Lucid Lynx)
- Tested on Ubuntu 11.10 (Oneiric Ocelot)

Please test on Windows and other Linux distributions

Change-Id: I132c01293fc0cff0cfb84556a93c0b8de8e57230
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/250
Tested-by: build bot (Jenkins)
Reviewed-by: Sven Schnelle <svens@stackframe.org>

util/crossgcc/patches/acpica-unix-20110922_unknown_warnings.patch

@@ -0,0 +1,19 @@
+--- acpica-unix-20110922/compiler/Makefile	2011-09-22 08:59:34.000000000 -0700
++++ acpica-unix-20110922/compiler/Makefile	2011-10-11 23:47:29.000000000 -0700
+@@ -245,15 +245,11 @@
+     -Waggregate-return \
+     -Wchar-subscripts \
+     -Wempty-body \
+-    -Wlogical-op \
+     -Wmissing-declarations \
+     -Wmissing-field-initializers \
+-    -Wmissing-parameter-type \
+     -Wnested-externs \
+-    -Wold-style-declaration \
+     -Wold-style-definition \
+-    -Wredundant-decls \
+-    -Wtype-limits
++    -Wredundant-decls
+ 
+ #
+ # Bison/Flex configuration