ALSA: portman2x4: Use bitwise instead of arithmetic operator for flags

Fix the following coccinelle warning:

sound/drivers/portman2x4.c:460:34-35: WARNING: sum of probable bitmasks, consider |

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Samuel Zou <zou_wei@huawei.com>
Link: https://lore.kernel.org/r/1588834135-14842-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c
index ecefa7c..38603cb 100644
--- a/sound/drivers/portman2x4.c
+++ b/sound/drivers/portman2x4.c
@@ -457,7 +457,7 @@ static int portman_probe(struct parport *p)
 
 	/* Set for RXDATA0 where no damage will be done. */
 	/* 5 */
-	parport_write_control(p, RXDATA0 + STROBE);	/* Write Strobe=1 to command reg. */
+	parport_write_control(p, RXDATA0 | STROBE);	/* Write Strobe=1 to command reg. */
 
 	/* 6 */
 	if ((parport_read_status(p) & ESTB) != ESTB)