eclass/cros-au: remove unused eclass

bootengine technically uses it, but doesn't actually call anything from
it. Remove it from bootengine then remove the eclass

sdk_container/src/third_party/coreos-overlay/eclass/cros-au.eclass

@@ -1,47 +0,0 @@
-# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
-# Distributed under the terms of the GNU General Public License v2
-
-#
-# Original Author: The Chromium OS Authors <chromium-os-dev@chromium.org>
-# Purpose: Library for handling packages that are part of Auto Update.
-#
-
-inherit flag-o-matic
-
-# Some boards started out 32bit (user/kernel) and then migrated to 64bit
-# (user/kernel).  Since we need to auto-update (AU) from the 32bit to
-# 64bit, and the old 32bit kernels can't execte 64bit code, we need to
-# always build the AU code as 32bit.
-#
-# Setup the build env to create 32bit objects.
-board_setup_32bit_au_env()
-{
-	[[ $# -eq 0 ]] || die "${FUNCNAME}: takes no arguments"
-
-	__AU_OLD_ARCH=${ARCH}
-	__AU_OLD_ABI=${ABI}
-	__AU_OLD_LIBDIR_x86=${LIBDIR_x86}
-	export ARCH=x86 ABI=x86 LIBDIR_x86="lib"
-	__AU_OLD_CHOST=${CHOST}
-	export CHOST=i686-pc-linux-gnu
-	__AU_OLD_SYSROOT=${SYSROOT}
-	export SYSROOT=/usr/${CHOST}
-	append-ldflags -L"${__AU_OLD_SYSROOT}"/usr/lib
-	append-cxxflags -isystem "${__AU_OLD_SYSROOT}"/usr/include
-}
-
-# undo what we did in the above function
-board_teardown_32bit_au_env()
-{
-	[[ $# -eq 0 ]] || die "${FUNCNAME}: takes no arguments"
-	[ -z "${__AU_OLD_SYSROOT}" ] && \
-		die "board_setup_32bit_au_env must be called first"
-
-	filter-ldflags -L"${__AU_OLD_SYSROOT}"/usr/lib
-	filter-flags -isystem "${__AU_OLD_SYSROOT}"/usr/include
-	export SYSROOT=${__AU_OLD_SYSROOT}
-	export CHOST=${__AU_OLD_CHOST}
-	export LIBDIR_x86=${__AU_OLD_LIBDIR_x86}
-	export ABI=${__AU_OLD_ABI}
-	export ARCH=${__AU_OLD_ARCH}
-}

sdk_container/src/third_party/coreos-overlay/sys-kernel/bootengine/bootengine-9999.ebuild

@@ -14,7 +14,7 @@ else
 	KEYWORDS="amd64 arm arm64 x86"
 fi
 
-inherit cros-workon cros-debug cros-au
+inherit cros-workon cros-debug
 
 DESCRIPTION="CoreOS Bootengine"
 SRC_URI=""