[IA64] Kdump: 64-bit aligned access to elf-note data

[IA64] Kdump: 64-bit aligned access to elf-note data

xen_core_regs, as passed by kexec_crash_save_info(), is 32-bit aligned as
it is the data section of an ELF-note. In order to ensure 64-bit aligned
access when xen_core_regs is filled in, shift it a bit and then memmove()
the data back into the 32-bit aligned location after the values have been
written.

Without this change kdump panics on an unaligned-access.

Signed-off-by: Simon Horman <horms@verge.net.au>