staging: ST_BT depends on RFKILL

Fix kconfig unmet dependency warning:

warning: (ST_BT && STAGING && !STAGING_EXCLUDE_BUILD && BT) selects TI_ST which has unmet direct dependencies (RFKILL)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/ti-st/Kconfig

@@ -16,7 +16,7 @@ config TI_ST
 
 config ST_BT
 	tristate "BlueZ bluetooth driver for ST"
-	depends on BT
+	depends on BT && RFKILL
 	select TI_ST
 	help
 	  This enables the Bluetooth driver for TI BT/FM/GPS combo devices.