ipq40xx: add MikroTik subtarget

MikroTik devices require the use of raw vmlinux out of the self
extracting compressed kernels.

They also require 4K sectors, kernel2minor, partition parser as well as
RouterBoard platform drivers.

So in order to not add unnecessary code to the generic sub target lets
introduce a MikroTik sub target.

Signed-off-by: Robert Marko <[email protected]>

target/linux/ipq40xx/Makefile

@@ -6,7 +6,7 @@ BOARDNAME:=Qualcomm Atheros IPQ40XX
 FEATURES:=squashfs fpu ramdisk nand
 CPU_TYPE:=cortex-a7
 CPU_SUBTYPE:=neon-vfpv4
-SUBTARGETS:=generic
+SUBTARGETS:=generic mikrotik
 
 KERNEL_PATCHVER:=5.4
 KERNEL_TESTING_PATCHVER:=5.4

target/linux/ipq40xx/mikrotik/target.mk

@@ -0,0 +1,4 @@
+BOARDNAME:=MikroTik
+FEATURES += minor
+KERNEL_IMAGES:=vmlinux
+IMAGES_DIR:=compressed