ALSA: ymfpci: Use register macro in place of integer literal

The macro for said register already exists, so just use it, to make the
code more readable.
Signed-off-by: Tasos Sahanidis <tasos@tasossah.com>
Link: https://lore.kernel.org/r/20230329043918.179352-1-tasos@tasossah.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/ymfpci/ymfpci_main.c

@@ -2214,7 +2214,7 @@ static void snd_ymfpci_free(struct snd_card *card)
 
 	snd_ymfpci_free_gameport(chip);
 	
-	pci_write_config_word(chip->pci, 0x40, chip->old_legacy_ctrl);
+	pci_write_config_word(chip->pci, PCIR_DSXG_LEGACY, chip->old_legacy_ctrl);
 	
 	release_firmware(chip->dsp_microcode);
 	release_firmware(chip->controller_microcode);