[ALSA] powermac - Fix typos

The kernel build fails, with following error
  CC      sound/ppc/tumbler.o
sound/ppc/tumbler.c: In function ‘snapper_get_capture_source’:
sound/ppc/tumbler.c:812: error: ‘union <anonymous>’ has no member named ‘value’
sound/ppc/tumbler.c: In function ‘snapper_put_capture_source’:
sound/ppc/tumbler.c:824: error: ‘union <anonymous>’ has no member named ‘enuemerated’
make[2]: *** [sound/ppc/tumbler.o] Error 1
make[1]: *** [sound/ppc] Error 2
make: *** [sound] Error 2

Signed-off-by: Kamalesh Babulal <kamalesh@linx.vnet.ibm.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>