configs/at91: refactor to use genimage.sh

Prefer the commom genimage.sh instead of a custom post-image.sh script.

Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

board/atmel/at91sam9x5ek_mmc/post-image.sh

@@ -1,20 +0,0 @@
-#!/bin/sh
-
-BOARD_DIR="$(dirname $0)"
-GENIMAGE_CFG="${BOARD_DIR}/genimage.cfg"
-GENIMAGE_TMP="${BUILD_DIR}/genimage.tmp"
-
-rm -rf "${GENIMAGE_TMP}"
-
-echo --rootpath "${TARGET_DIR}"
-echo --tmppath "${GENIMAGE_TMP}"
-echo --inputpath "${BINARIES_DIR}"
-echo --outputpath "${BINARIES_DIR}"
-echo --config "${GENIMAGE_CFG}"
-
-genimage                               \
-	--rootpath "${TARGET_DIR}"     \
-	--tmppath "${GENIMAGE_TMP}"    \
-	--inputpath "${BINARIES_DIR}"  \
-	--outputpath "${BINARIES_DIR}" \
-	--config "${GENIMAGE_CFG}"