x86/boot: Add missing bootparam that breaks boot on some platforms

Change

  a90118c445cc x86/boot: Save fields explicitly, zero out everything else

modified the way boot parameters were saved on x86.  When this was
backported, e820_table didn't exists, and that change was dropped.
Unfortunately, e820_table did exist, it was just named e820_map
in this kernel version.

This was breaking booting on a Supermicro Super Server/A2SDi-2C-HLN4F
with a Denverton CPU.  Adding e820_map to the saved boot params table
fixes the issue.

Cc: <stable@vger.kernel.org> # 4.9.x, 4.4.x
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>