MX53: drop config.mk from mx53evk

The config.mk file in board directory is now obsolete and
should be removed. Add option for the IMX image into
boards.cfg

Signed-off-by: Jason Liu <r64343@freescale.com>

board/freescale/mx53evk/config.mk

-#
-# Copyright 2010 Freescale Semiconductor, Inc. All Rights Reserved.
-#
-# See file CREDITS for list of people who contributed to this
-# project.
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License as
-# published by the Free Software Foundation; either version 2 of
-# the License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
-# MA 02111-1307 USA
-#
-
-IMX_CONFIG = $(SRCTREE)/board/$(BOARDDIR)/imximage.cfg
-ALL += $(obj)u-boot.imx

boards.cfg

@@ -109,7 +109,7 @@ dkb			     arm         arm926ejs   -                   Marvell        pantheon
 ca9x4_ct_vxp                 arm         armv7       vexpress            armltd
 efikamx                      arm         armv7       efikamx             -              mx5
 mx51evk                      arm         armv7       mx51evk             freescale      mx5		mx51evk:IMX_CONFIG=board/freescale/mx51evk/imximage.cfg
-mx53evk                      arm         armv7       mx53evk             freescale      mx5
+mx53evk                      arm         armv7       mx53evk             freescale      mx5		mx53evk:IMX_CONFIG=board/freescale/mx53evk/imximage.cfg
 vision2                      arm         armv7       vision2             ttcontrol      mx5
 cm_t35                       arm         armv7       cm_t35              -              omap3
 omap3_overo                  arm         armv7       overo               -              omap3