x86/boot: Fix boot regression caused by bootparam sanitizing

commit a90118c4 ("x86/boot: Save fields explicitly, zero out everything
else") had two errors:

    * It preserved boot_params.acpi_rsdp_addr, and
    * It failed to preserve boot_params.hdr

Therefore, zero out acpi_rsdp_addr, and preserve hdr.

Fixes: a90118c4 ("x86/boot: Save fields explicitly, zero out everything else")
Reported-by: Neil MacLeod <neil@nmacleod.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Neil MacLeod <neil@nmacleod.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190821192513.20126-1-jhubbard@nvidia.com

arch/x86/include/asm/bootparam_utils.h

@@ -59,7 +59,6 @@ static void sanitize_boot_params(struct boot_params *boot_params)
 			BOOT_PARAM_PRESERVE(apm_bios_info),
 			BOOT_PARAM_PRESERVE(tboot_addr),
 			BOOT_PARAM_PRESERVE(ist_info),
-			BOOT_PARAM_PRESERVE(acpi_rsdp_addr),
 			BOOT_PARAM_PRESERVE(hd0_info),
 			BOOT_PARAM_PRESERVE(hd1_info),
 			BOOT_PARAM_PRESERVE(sys_desc_table),
@@ -71,6 +70,7 @@ static void sanitize_boot_params(struct boot_params *boot_params)
 			BOOT_PARAM_PRESERVE(eddbuf_entries),
 			BOOT_PARAM_PRESERVE(edd_mbr_sig_buf_entries),
 			BOOT_PARAM_PRESERVE(edd_mbr_sig_buffer),
+			BOOT_PARAM_PRESERVE(hdr),
 			BOOT_PARAM_PRESERVE(e820_table),
 			BOOT_PARAM_PRESERVE(eddbuf),
 		};