sunhme endianness annotations

	This one is interesting - SBUS and PCI variants have
opposite endianness in descriptors (SBUS is sparc-only, so there
host-endian == big-endian).

	Solution: declare a bitwise type (hme32) and in accessor
helpers do typechecking and force-casts (once we know that the
type is right).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>