[PATCH] x86: Update cbmem driver

[Nable]

On 15.08.2023 01:42, Simon Glass:
> I believe the original intent was to indicate that the buffer had
> overflowed. But prompted by your review I took a look at the coreboot
> implementation and it now has an overflow flag.
>
> So I will send a v2 incorporating this.
Thank you for this investigation, v2 approach definitely makes sense.
Btw, is there any reason to mark 'struct cbmem_console' as packed?