ioport: remove LITTLE_ENDIAN mark for portio

Setting it to LE forces a byte swap when host != guest endian but
this makes no sense at all.

Herve made the suggestion upon observing that word writes/reads
were broken into byte writes/reads in such a way as to assume
devices are interpret registers as LE.

However, even if this were a problem, marking the region as LE is
not useful because what's essentially happening here is that LE is
open coded.  So by marking it LE in MemoryRegionOps, we're doing a
superflous swap.

Now, the portio code is suspicious to begin with.  The dispatch
layer really has no purpose in splitting I/O requests in the first
place...

Cc: Hervé Poussineau <hpoussin@reactos.org>
Cc: Alex Graf <agraf@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

ioport.c

@@ -183,7 +183,6 @@ static void portio_write(void *opaque, hwaddr addr, uint64_t data,
 static const MemoryRegionOps portio_ops = {
     .read = portio_read,
     .write = portio_write,
-    .endianness = DEVICE_LITTLE_ENDIAN,
     .valid.unaligned = true,
     .impl.unaligned = true,
 };