ALSA: emu10k1: fix snd_emu1010_fpga_read() input masking for rev2 cards

Unlike the Alice2 chips used on 1st generation E-MU cards, the
Tina/Tina2 chips used on the 2nd gen cards have only six GPIN pins,
which means that we need to use a smaller mask. Failure to do so would
falsify the read data if the FPGA tried to raise an IRQ right at that
moment. This wasn't a problem so far, as we didn't actually enable FPGA
IRQs, but that's going to change soon.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230422132430.1057490-1-oswald.buddenhagen@gmx.de


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