adm8668: remove linux 3.3 support

target/linux/adm8668/config-3.3

target/linux/adm8668/files-3.3/arch/mips/adm8668/Kconfig

target/linux/adm8668/files-3.3/arch/mips/adm8668/Makefile

target/linux/adm8668/files-3.3/arch/mips/adm8668/Platform

target/linux/adm8668/files-3.3/arch/mips/adm8668/clock.c

.../linux/adm8668/files-3.3/arch/mips/adm8668/early_printk.c

target/linux/adm8668/files-3.3/arch/mips/adm8668/gpio.c

target/linux/adm8668/files-3.3/arch/mips/adm8668/irq.c

target/linux/adm8668/files-3.3/arch/mips/adm8668/platform.c

target/linux/adm8668/files-3.3/arch/mips/adm8668/prom.c

target/linux/adm8668/files-3.3/arch/mips/adm8668/setup.c

target/linux/adm8668/files-3.3/arch/mips/adm8668/time.c

target/linux/adm8668/files-3.3/arch/mips/adm8668/u-boot.h

...68/files-3.3/arch/mips/include/asm/mach-adm8668/adm8668.h

.../files-3.3/arch/mips/include/asm/mach-adm8668/asm/sizes.h

...m8668/files-3.3/arch/mips/include/asm/mach-adm8668/gpio.h

...dm8668/files-3.3/arch/mips/include/asm/mach-adm8668/irq.h

...dm8668/files-3.3/arch/mips/include/asm/mach-adm8668/war.h

target/linux/adm8668/files-3.3/arch/mips/pci/pci-adm8668.c

target/linux/adm8668/files-3.3/drivers/mtd/maps/adm8668.c