linux-firmware: update Marvell PCIe-USB8997 firmware image

Firmware version for this image is 16.68.1.p97

In PCIe-USB chipset, WLAN is over PCIe whereas bluetooth is over
USB.
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

@@ -757,7 +757,7 @@ File: mrvl/pcieuart8997_combo_v4.bin
 Version: 16.68.1.p70
 
 File: mrvl/pcieusb8997_combo_v4.bin
-Version: 16.68.1.p70
+Version: 16.68.1.p97
 
 Licence: Redistributable. See LICENCE.Marvell for details.  Originates from
 http://git.marvell.com/?p=mwifiex-firmware.git