functions for external storage of seq in/out lengths,
i.e., for 32-bit lengths.

These type-dependent functions automatically determine whether to
store the length internally (embedded in the command header word) or
externally (after the address pointer), based on size of the type
given.
Signed-off-by: Yuan Kang <Yuan.Kang@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>