Import upstream zstd v1.5.5 to expose upstream's QAT integration.

Import from upstream commit 58b3ef79 [0]. This is one commit before the
tag v1.5.5-kernel [1], which is signed with upstream's signing key. The
next patch in the series imports from v1.5.5-kernel, and is included in
the series, rather than just importing directly from v1.5.5-kernel,
because it is a non-trivial patch applied to improve the kernel's
decompression speed. This commit contains 3 backported patches on top of
v1.5.5: Two from the Linux copy of zstd, and one from upstream's `dev`
branch.

In addition to keeping the kernel's copy of zstd up to date, this update
was requested by Intel to expose upstream zstd's external match provider
API to the kernel, which allows QAT to accelerate the LZ match finding
stage.

This commit was generated by:

  export ZSTD=/path/to/repo/zstd/
  export LINUX=/path/to/repo/linux/
  cd "$ZSTD/contrib/linux-kernel"
  git checkout v1.5.5-kernel~
  make import LINUX="$LINUX"

I tested and benchmarked this commit on x86-64 with gcc-13.2.1 on an
Intel i9-9900K by running my benchmark scripts that benchmark zstd's
performance in btrfs and squashfs compressed filesystems. This commit
improves compression speed, especially for higher compression levels,
and regresses decompression speed. But the decompression speed
regression is addressed by the next patch in the series.

Component,	Level,	C. time delta,	size delta,	D. time delta
Btrfs    ,	    1,	        -1.9%,	     +0.0%,	        +9.5%
Btrfs    ,	    3,	        -5.6%,	     +0.0%,	        +7.4%
Btrfs    ,	    5,	        -4.9%,	     +0.0%,	        +5.0%
Btrfs    ,	    7,	        -5.7%,	     +0.0%,	        +5.2%
Btrfs    ,	    9,	        -5.7%,	     +0.0%,	        +4.0%
Squashfs ,	    1,	          N/A,	      0.0%,	       +11.6%

I also boot tested with a zstd compressed kernel on i386 and aarch64.

Link: https://github.com/facebook/zstd/commit/58b3ef79eb9f1e6613684ea6e5b89720660ee8b6
Link: https://github.com/facebook/zstd/tree/v1.5.5-kernel


Signed-off-by: Nick Terrell <terrelln@fb.com>