Since the CPU is generating an exception when accessing unaligned word, and
as this exception is not yet handled when running prom_init, data should be
copied from the architecture vector byte per byte.
Signed-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>