x86: Fix a section mismatch in arch/x86/kernel/setup.c

copy_edd() should be __init.
warning msg:
WARNING: vmlinux.o(.text+0x7759): Section mismatch in reference from the
function copy_edd() to the variable .init.data:boot_params
The function copy_edd() references
the variable __initdata boot_params.
This is often because copy_edd lacks a __initdata
annotation or the annotation of boot_params is wrong.

Signed-off-by: ZhenwenXu <helight.xu@gmail.com>
LKML-Reference: <4B139F8F.4000907@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>