brcmfmac: Add DMI nvram filename quirk for Voyo winpad A15 tablet

The Voyo winpad A15 tablet contains quite generic names in the sys_vendor
and product_name DMI strings, without this patch brcmfmac will try to load:
rcmfmac4330-sdio.To be filled by O.E.M.-To be filled by O.E.M..txt
as nvram file which is a bit too generic.

Add a DMI quirk so that a unique and clearly identifiable nvram file name
is used on the Voyo winpad A15 tablet.

While preparing a matching linux-firmware update I noticed that the nvram
is identical to the nvram used on the Prowise-PT301 tablet, so the new DMI
quirk entry simply points to the already existing Prowise-PT301 nvram file.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210129171413.139880-2-hdegoede@redhat.com