[SeaBIOS] [PATCH for-1.10-stable] drop "etc/boot-cpus" fw_cfg file and reuse legacy QEMU_CFG_NB_CPUS

[Kevin O'Connor]

On Fri, Nov 11, 2016 at 04:35:15PM +0100, Igor Mammedov wrote:
> since QEMU_CFG_NB_CPUS not going away anytime soon
> and serves the same purpose as just added "etc/boot-cpus" fw_cfg
> drop support for "etc/boot-cpus" while this code is not
> in use yet (i.e. QEMU with "etc/boot-cpus" hasn't been released)
> and reuse QEMU_CFG_NB_CPUS instead of it.

I'm okay with this change.  I'd like to get Gerd's comments as well
though as the patch is targeted for a stable branch.

-Kevin