imx6: rename target to 'imx'

This is first step in migrating to a generic i.MX target which in the
next steps will also get divided into arch-specific subtargets.

In the result, this will make it possible to support, within a single
target, also other modern NXP i.MX families, like the i.MX 7, i.MX 8
or recently introduced i.MX 9.

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

target/linux/imx/image/bootscript-toradex_apalis

@@ -0,0 +1,21 @@
+echo "Toradex Apalis OpenWrt Boot script v1.1"
+
+run emmcfinduuid
+
+setenv nextcon 0
+setenv boot_file uImage
+setenv fdt_file imx6q-apalis-ixora.dtb
+setenv root root=PARTUUID=${uuid} rootfstype=squashfs rootwait
+setenv bootargs earlyprintk console=${console},${baudrate}n8 ${root}
+setenv fsload ext4load mmc ${emmcdev}:${emmcbootpart}
+
+if ${fsload} ${kernel_addr_r} ${boot_file}; then
+	if ${fsload} ${fdt_addr_r} ${fdt_file}; then
+		test -n "$fdt_fixup" && run fdt_fixup
+		bootm ${kernel_addr_r} - ${fdt_addr_r}
+	else
+		echo "Error loading device-tree"
+	fi
+else
+	echo "Error loading kernel image"
+fi