x86: Provide default SMBIOS manufacturer/product

Add a file containing defaults for these, using the existing CONFIG
options. This file must be included with #include since it needs to
be passed through the C preprocessor.

Enable the driver for all x86 boards that generate SMBIOS tables.
Disable it for coral since it has its own driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: reword the commit message a little bit]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>