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

BugLink: https://bugs.launchpad.net/bugs/1845405

Change

  a90118c4 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>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/include/asm/bootparam_utils.h

@@ -71,6 +71,7 @@ static void sanitize_boot_params(struct boot_params *boot_params)
 			BOOT_PARAM_PRESERVE(edd_mbr_sig_buf_entries),
 			BOOT_PARAM_PRESERVE(edd_mbr_sig_buffer),
 			BOOT_PARAM_PRESERVE(hdr),
+			BOOT_PARAM_PRESERVE(e820_map),
 			BOOT_PARAM_PRESERVE(eddbuf),
 		};