ALSA: atmel: Remove leftovers of AVR32 removal

The ALSA related include header files are left overs after the commit

	020c5260 ("ALSA: atmel: Remove AVR32 bits from the driver")

Fixes: 020c5260

 ("ALSA: atmel: Remove AVR32 bits from the driver")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>