wl12xx: move hardcoded hci_io_ds value into the conf struct

Instead of hardcoding the hci_io_ds configuration that we write to the
SDIO_IO_DS top registed, read it from the default configuration so
that it's easier to change for different platforms.

Reported-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/conf.h b/drivers/net/wireless/wl12xx/conf.h
index 743bd0b..52269d4 100644
--- a/drivers/net/wireless/wl12xx/conf.h
+++ b/drivers/net/wireless/wl12xx/conf.h
@@ -1206,6 +1206,7 @@
 	struct conf_ht_setting ht;
 	struct conf_memory_settings mem_wl127x;
 	struct conf_memory_settings mem_wl128x;
+	u8 hci_io_ds;
 };
 
 #endif