brcmfmac: Set board_type from DMI on x86 based machines

For x86 based machines, set the board_type used for nvram file selection
based on the DMI sys-vendor and product-name strings.

Since on some models these strings are too generic, this commit also adds
a quirk table overriding the strings for models listed in that table.

The board_type setting is used to load the board-specific nvram file with
a board-specific name so that we can ship files for each supported board
in linux-firmware.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>