ALSA: emu10k1: hide absent 2nd pointer-offset register set from /proc

The 2nd register set belongs to the P16V chip (or embedded P17V module),
so there is nothing to show when no such part is present. Gen2 E-MU
cards have a P17V, but it's entirely unused, so we hide it there as
well.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230526101659.437969-2-oswald.buddenhagen@gmx.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>