x86: baytrail: fsp: Move Azalia update codes to board

Azalia configuration may be different across boards, hence it's not
appropriate to do that in the SoC level. Instead, let's make the
SoC update_fsp_azalia_configs() routine as a weak version, and do
the actual work in the board codes.

So far it seems only som-db5800-som-6867 board enables the Azalia.
Move the original codes into som-db5800-som-6867.c.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>