oxnas: kill old oxnas target

target/linux/oxnas/Makefile

target/linux/oxnas/base-files/etc/board.d/01_leds

target/linux/oxnas/base-files/etc/board.d/02_network

target/linux/oxnas/base-files/etc/diag.sh

target/linux/oxnas/base-files/init.d/set-irq-affinity

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

...linux/oxnas/base-files/lib/preinit/01_preinit_do_oxnas.sh

target/linux/oxnas/base-files/lib/upgrade/platform.sh

target/linux/oxnas/config-4.4

target/linux/oxnas/files/arch/arm/boot/dts/ox820-akitio.dts

target/linux/oxnas/files/arch/arm/boot/dts/ox820-kd20.dts

...inux/oxnas/files/arch/arm/boot/dts/ox820-pogoplug-pro.dts

...linux/oxnas/files/arch/arm/boot/dts/ox820-pogoplug-v3.dts

target/linux/oxnas/files/arch/arm/boot/dts/ox820-stg212.dts

target/linux/oxnas/files/arch/arm/boot/dts/ox820.dtsi

target/linux/oxnas/files/arch/arm/configs/ox820_defconfig

target/linux/oxnas/files/arch/arm/mach-oxnas/Kconfig

target/linux/oxnas/files/arch/arm/mach-oxnas/Makefile

target/linux/oxnas/files/arch/arm/mach-oxnas/Makefile.boot

target/linux/oxnas/files/arch/arm/mach-oxnas/fiq.S