mwifiex: correct antenna number with high bits reserved

High bits of antenna number are reserved in hardware spec,
using low 4 bits represent supported antenna.
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Xinming Hu <huxm@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/cmdevt.c

@@ -1529,7 +1529,8 @@ int mwifiex_ret_get_hw_spec(struct mwifiex_private *priv,
 
 	adapter->fw_release_number = le32_to_cpu(hw_spec->fw_release_number);
 	adapter->fw_api_ver = (adapter->fw_release_number >> 16) & 0xff;
-	adapter->number_of_antenna = le16_to_cpu(hw_spec->number_of_antenna);
+	adapter->number_of_antenna =
+			le16_to_cpu(hw_spec->number_of_antenna) & 0xf;
 
 	if (le32_to_cpu(hw_spec->dot_11ac_dev_cap)) {
 		adapter->is_hw_11ac_capable = true;