linux-firmware: update Marvell PCIe-USB8997 wifi-only firmware image

During PCIe reset, wifi-only firmware will be download to device
in case bluetooth part do not get affected.

Firmware version for this image is 16.68.1.p97
Signed-off-by: Xinming Hu <huxm@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>

WHENCE

@@ -759,6 +759,9 @@ Version: 16.68.1.p70
 File: mrvl/pcieusb8997_combo_v4.bin
 Version: 16.68.1.p97
 
+File: mrvl/pcie8997_wlan_v4.bin
+Version: 16.68.1.p97
+
 Licence: Redistributable. See LICENCE.Marvell for details.  Originates from
 http://git.marvell.com/?p=mwifiex-firmware.git