linux-firmware: update Marvell SD8887 firmware image

Firmware version for this image is 15.68.1.p71
The image can be downloaded through either WLAN or
Bluetooth.

Signed-off-by: Xinming Hu <huxm@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>

WHENCE

@@ -745,7 +745,7 @@ File: mrvl/pcie8897_uapsta.bin
 Version: 15.68.7.p77
 
 File: mrvl/sd8887_uapsta.bin
-Version: 15.68.7.p5
+Version: 15.68.7.p71
 
 File: mrvl/sd8801_uapsta.bin
 Version: 14.68.36.p60