unix: add Linux crypto configuration API constants and types

Change-Id: I447150cb60b5580cee77d23c0dae2244803e92ef
Reviewed-on: https://go-review.googlesource.com/c/sys/+/173660
Run-TryBot: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

unix/mkerrors.sh

@@ -222,6 +222,7 @@ struct ltchars {
 #include <linux/hdreg.h>
 #include <linux/rtc.h>
 #include <linux/if_xdp.h>
+#include <linux/cryptouser.h>
 #include <mtd/ubi-user.h>
 #include <net/route.h>
 
@@ -499,6 +500,7 @@ ccflags="$@"
 		$2 ~ /^NFN/ ||
 		$2 ~ /^XDP_/ ||
 		$2 ~ /^(HDIO|WIN|SMART)_/ ||
+		$2 ~ /^CRYPTO_/ ||
 		$2 !~ "WMESGLEN" &&
 		$2 ~ /^W[A-Z0-9]+$/ ||
 		$2 ~/^PPPIOC/ ||