mwifiex: add support for Marvell USB8797 chipset

This patch supports Avastar 88W8797 chipset with USB interface.

The corresponding firmware image file is located at:
"mrvl/usb8797_uapsta.bin"

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Kiran Divekar <dkiran@marvell.com>
Signed-off-by: Frank Huang <frankh@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/sta_cmd.c b/drivers/net/wireless/mwifiex/sta_cmd.c
index 1f71105..87ed2a1 100644
--- a/drivers/net/wireless/mwifiex/sta_cmd.c
+++ b/drivers/net/wireless/mwifiex/sta_cmd.c
@@ -1293,7 +1293,7 @@
 	if (ret)
 		return -1;
 
-	if (first_sta) {
+	if (first_sta && (priv->adapter->iface_type != MWIFIEX_USB)) {
 		/* Enable auto deep sleep */
 		auto_ds.auto_ds = DEEP_SLEEP_ON;
 		auto_ds.idle_time = DEEP_SLEEP_IDLE_TIME;