MFC r228526 (by kevlo):
s/timout/timeout
MFC r242827 (by rdivacky):
Give tw_osl_dbg_printf format string to pacify clang warning.
MFC r248583 (by kib):
Fix twa(4) after the r246713.  The driver copies data around to
satisfy some alignment restrictions.  Do not set TW_OSLI_REQ_FLAGS_CCB
flag for mapped data, pass the csio->data_ptr in the req->data.

Do not put the ccb pointer into req->data ever, ccb is stored in
req->orig_req already.

Submitted by:	Shuichi KITAGUCHI <ki@hh.iij4u.or.jp>
PR:		kern/177020
MFC: r248804

deferal -> deferral

MFC: r248891

Pass correct parameter to CTR5() in bus_dmamap_load_uio.

MFC: r248892

Do not add 1 to nsegs before passing to CTR5(), since nsegs
has already been incremented before these calls.

MFC: r248893

Add CTR5() to bus_dmamap_load_ccb, similar to other bus_dmamap_load_*
functions.

MFC: r248896

Add bus_dmamap_load_bio for non-CAM disk drivers that wish to enable
unmapped I/O.

MFC: r249025

Add support for XPT_CONT_TARGET_IO CCBs in _bus_dmamap_load_ccb().

Declare CCB types in their respective switch blocks.

MFC: r249538

Some compilers issue a warning when wider integer is casted to narrow
pointer.  Supposedly shut down the warning by casting through
uintptr_t.

MFC: r251221

Move an assertion to the right spot; only bus_dmamap_load_mbuf(9)
requires a pkthdr being present but that's not the case for either
_bus_dmamap_load_mbuf_sg() or bus_dmamap_load_mbuf_sg(9).