avr32: Move cpu/at32ap/* to arch/avr32/cpu/*

arch/avr32/cpu/Makefile

arch/avr32/cpu/at32ap700x/Makefile

arch/avr32/cpu/at32ap700x/clk.c

arch/avr32/cpu/at32ap700x/portmux.c

arch/avr32/cpu/at32ap700x/sm.h

arch/avr32/cpu/cache.c

arch/avr32/cpu/config.mk

arch/avr32/cpu/cpu.c

arch/avr32/cpu/exception.c

arch/avr32/cpu/hsdramc.c

arch/avr32/cpu/hsdramc1.h

arch/avr32/cpu/hsmc3.h

arch/avr32/cpu/interrupts.c

arch/avr32/cpu/pio2.h

arch/avr32/cpu/portmux-gpio.c

arch/avr32/cpu/portmux-pio.c

arch/avr32/cpu/start.S

board/mimc/mimc200/mimc200.c