[ALSA] mpu-401: remove MPU401_INFO_UART_ONLY flag

Since the last patch made the ENTER_UART command optional, the
enter_uart option and its corresponding flag have become superfluous.
The uart_enter option remains for backward compatibility but just prints
a warning when used.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/drivers/mpu401/mpu401_uart.c b/sound/drivers/mpu401/mpu401_uart.c
index b5c5dd1..43c6f20 100644
--- a/sound/drivers/mpu401/mpu401_uart.c
+++ b/sound/drivers/mpu401/mpu401_uart.c
@@ -270,8 +270,7 @@
 {
 	if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
 		return -EIO;
-	if (!(mpu->info_flags & MPU401_INFO_UART_ONLY) &&
-	    snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
+	if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
 		return -EIO;
 	return 0;
 }