[ALSA] emu10k1 - Fix ABI for older ld10k1

Fix ABI for older ld10k1.  When no EMU10K1_PVERSION ioctl is issued,
the driver accepts ioctls with the old struct size without TLV information.
Also, changed the struct field to make the conversion easier from the
old to the new structs.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>