imx: split into arch-specific subtargets

Modern NXP i.MX series includes several different families, based on
single- or multi-core Arm Cortex-A CPUs. To be able to support more
families within a single target, we split the 'imx' in arch-specific
subtargets, starting with 'cortexa9' for the Cortex-A9 based i.MX 6,
already supported by the original 'imx6' target.

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

target/linux/imx/base-files/lib/imx.sh

@@ -1,30 +0,0 @@
-#
-# Copyright (C) 2010-2013 OpenWrt.org
-#
-
-rootpartuuid() {
-	local cmdline=$(cat /proc/cmdline)
-	local bootpart=${cmdline##*root=}
-	bootpart=${bootpart%% *}
-	local uuid=${bootpart#PARTUUID=}
-	echo ${uuid%-02}
-}
-
-bootdev_from_uuid() {
-	blkid | grep "PTUUID=\"$(rootpartuuid)\"" | cut -d : -f1
-}
-
-bootpart_from_uuid() {
-	blkid | grep $(rootpartuuid)-01 | cut -d : -f1
-}
-
-rootpart_from_uuid() {
-	blkid | grep $(rootpartuuid)-02 | cut -d : -f1
-}
-
-apalis_mount_boot() {
-	mkdir -p /boot
-	[ -f /boot/uImage ] || {
-		mount -o rw,noatime $(bootpart_from_uuid) /boot > /dev/null
-	}
-}