wifi: mwifiex: Add missing MODULE_FIRMWARE() for SD8801

The module metadata for the firmware file mrvl/sd8801_uapsta.bin
is missing.

Signed-off-by: Víctor Gonzalo <victor.gonzalo@anddroptable.net>
Acked-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240313183156.2234301-1-victor.gonzalo@anddroptable.net