Added MPU401_INFO_NO_ACK bitflag to ignore the ACK check for UART
commands.  VT172x doesn't handle ACK commands, for example.
Tested-by: Pavel Hofman <pavel.hofman@insite.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
 #define MPU401_INFO_INTEGRATED (1 << 2)        /* integrated h/w port */
 #define MPU401_INFO_MMIO       (1 << 3)        /* MMIO access */
 #define MPU401_INFO_TX_IRQ     (1 << 4)        /* independent TX irq */
+#define MPU401_INFO_NO_ACK     (1 << 6)        /* No ACK cmd needed */
 
 #define MPU401_MODE_BIT_INPUT          0
 #define MPU401_MODE_BIT_OUTPUT         1
 
 #endif
        }
        mpu->write(mpu, cmd, MPU401C(mpu));
-       if (ack) {
+       if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
                ok = 0;
                timeout = 10000;
                while (!ok && timeout-- > 0) {
 
                        if ((err = snd_mpu401_uart_new(card, 0, MPU401_HW_ICE1712,
                                                       ICEREG1724(ice, MPU_CTRL),
                                                       (MPU401_INFO_INTEGRATED |
+                                                       MPU401_INFO_NO_ACK |
                                                        MPU401_INFO_TX_IRQ),
                                                       ice->irq, 0,
                                                       &ice->rmidi[0])) < 0) {