sparc64: Hibernation support

This patch adds CONFIG_HIBERNATION support for sparc64
architecture. The suspend function is the same as on another
platforms. The restore function uses Bypass feature of MMU
which allows to make the process more comfortable and plesant.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
CC: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>