x86 PM: move 64-bit hibernation files to arch/x86/power

Move arch/x86/kernel/suspend_64.c to arch/x86/power .

Move arch/x86/kernel/suspend_asm_64.S to arch/x86/power
as hibernate_asm_64.S .

Update purpose and copyright information in
arch/x86/power/suspend_64.c and
arch/x86/power/hibernate_asm_64.S .

Update the Makefiles in arch/x86, arch/x86/kernel and
arch/x86/power to reflect the above changes.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>