thinkpad-acpi: don't take the first ALSA slot by default

We don't want to be the first soundcard.  We don't want to shift other
soundcards out of the way either, even if they load much later.

Ask ALSA to (by default) load us in one of the last three slots.  This
can be overriden at will using the "index" parameter.
Reported-by: Whoopie <whoopie79@gmx.net>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/thinkpad_acpi.c

@@ -6388,7 +6388,7 @@ static struct ibm_struct brightness_driver_data = {
 #define TPACPI_ALSA_SHRTNAME "ThinkPad Console Audio Control"
 #define TPACPI_ALSA_MIXERNAME TPACPI_ALSA_SHRTNAME
 
-static int alsa_index = SNDRV_DEFAULT_IDX1;
+static int alsa_index = ~((1 << (SNDRV_CARDS - 3)) - 1); /* last three slots */
 static char *alsa_id = "ThinkPadEC";
 static int alsa_enable = SNDRV_DEFAULT_ENABLE1;