E820_RESERVED_KERN was introduced to do early allocation for
setup_data when we were using original early_res with e820 map.
Now we are using memblock to do early resource reserve/allocation, and
setup_data is reserved in memblock early already.
For kexec path, kexec generate setup_data (Now kexec-tools create SETUP_EFI
and SETUP_E820_EXT), and pass pointer to second kernel, and
second kernel reserve setup_data by their own without using e820 map.
So we do not need to touch e820 map at all, and we can kill
E820_RESERVED_KERN.
That make the code simpler, and at same time that will fix bug with
hibernation:
mark_nonsave_region that can not handle that case:
E820_RAM and E820_RESERVED_KERN ranges are continuous and
boundary is not page aligned.
Link: https://bugzilla.opensuse.org/show_bug.cgi?id=913885
Link: https://bugzilla.kernel.org/show_bug.cgi?id=96111