Simplify assembler in ivy.c.  Move the copying of the random bits into
buffer from asm to C, which reduces amount of arguments for inline asm
and simplifies constraints.  Use unsigned types consistently.

Submitted by:	bde
Approved by:	secteam (delphij)
Reviewed by:	markm
MFC after:	1 week
Add DEV_MODULE_ORDERED().

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week