PR misc/49356 remove unnecessary references to atf-c/config.h

The function included via this header is not used and is removed in
later versions of atf, so let us avoid it.
Merge https://github.com/torvalds/linux/commit/2e7eeeb59a92d09144fdb7d2dc1af77a10a7945b#diff-528092536eaeb3c5f7ff6dfeed53786d

> drm/i915: set backlight duty cycle after backlight enable for gen4
> For reasons I can't claim to fully understand gen4 seems to require
> backlight duty cycle setting after the backlight has been enabled, or
> else black screen follows. I don't have documentation for the correct
> sequence on gen4 either. Confirmed on Dell Latitude D630 and MacBook4,1.

Without this patch, the screen on my T61 (i965) would be blank at boot
unless I booted with the AC adapter unplugged.
 Add #include <inttypes.h> for intmax_t to fix compile error.
Add ioctl to autodiscover wedges.
Be less noisy when handling wedge name conflicts.
Handle disks with non DEV_BSIZE sectors.
get sector size from disk structure.
Implement DIOCMWEDGES ioctl that triggers wedge autodiscovery.
Also fix a reference counting bug and clean up some code.
support DIOCMWEDGES ioctl.
Add 'makewedges' option to autodiscover wedges from a changed label.
Thankfully, apropos returns all results by default these days.  Remove
outdated sentence referring to the original (well, old new) limit of 10.
Fix PUFFS node use-after-reclaim

When puffs_cookie2vnode() misses an entry, vcache_get()
creates a new node (puffs_vfsop_loadvnode being called to
initialize the PUFFS part), then it discovers it is VNON,
and tries to vrele() it. vrele() calls VOP_INACTIVE(),
which led us in puffs_vnop_inactive() where we sent a
request to the filesystem for a node that already had been
reclaimed.

The fix is to check for VNON nodes in puffs_vnop_inactive()
and to return without doing anyting. This is suboptimal, but
a better workaround would probably need to modify vcache API,
with an impact on other filesystems. Let us keep it simple.
PUFFS direct I/O cache fix

There are a few situations where we must take care of the cache if direct
I/O was enabled:
- if we do direct I/O for write but not for read, then any write must
  invalidate the cache so that a reader gets the written data and not
  the not-updated cache.
- if we used a vnode without direct I/O and it is enabled for writing,
  we must flush the cache before compeling the open operation, so that
  the cachec write are not lost.

And at inactive time, we wipe direct I/O flags so that a new open without
direct I/O does not inherit direct I/O.
Restore build with -DDEBUG, and avoid a spurious diagnostic error with -DDEBUG
This code should be MP-safe. Use IPL_SCHED in place of IPL_DRM/IPL_VM and set
D_MPSAFE flag in cdevsw.
Do not release secmodels_lock when it is not held.

Sent on tech-kern@, ok lars@
sun4v: Removed a bunch of ifdef SUN4V since the CPU_ISSUN4V already has the necessary logic. Noticed by mrg@
Rebase awinrtc(4) year from 1970 to 1900.
Fixes +70 year RTC offset when dual booting with Android on Cubietruck.

Also a trailing whitespace fix.
Use autoconf for rump kernel posix hypercall layer.

This gets rid of homegrown hacks and puts all probes in one place.

Tested for NetBSD (build.sh + anita) and Linux (buildrump.sh)
RTC base year cannot be 1900 on A31 because the year field is only 6 bits wide; undo r1.5