Fix AC97 build breakage with converting to the shared AT91/AVR32 AC97 driver:
  struct atmel_ac97_data  -> struct ac97c_platform_data
  CONFIG_SND_AT91_AC97 -> CONFIG_SND_ATMEL_AC97C
Signed-off-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>