dk: support ZFS

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

After creating a gpt entry with type fbsd-zfs I noticed that it's not
recognized by dk(4).

dk5 at wd2: "ZFS_202003", 3907029101 blocks at 34, type: <unknown>

The attached diff fixes it:

dk5 at wd2: "ZFS_202003", 3907029101 blocks at 34, type: zfs

Ok to commit, or is more needed?
 Thomas

Index: dev/dkwedge/dkwedge_gpt.c
===================================================================
RCS file: /cvsroot/src/sys/dev/dkwedge/dkwedge_gpt.c,v
retrieving revision 1.24
diff -u -r1.24 dkwedge_gpt.c
--- dev/dkwedge/dkwedge_gpt.c	9 Jul 2019 17:06:46 -0000	1.24
+++ dev/dkwedge/dkwedge_gpt.c	29 Mar 2020 07:55:59 -0000
@@ -78,6 +78,7 @@
 	{ GPT_ENT_TYPE_VMWARE_RESERVED,		DKW_PTYPE_VMWRESV },
 	{ GPT_ENT_TYPE_MS_BASIC_DATA,		DKW_PTYPE_NTFS },
 	{ GPT_ENT_TYPE_LINUX_DATA,		DKW_PTYPE_EXT2FS },
+	{ GPT_ENT_TYPE_FREEBSD_ZFS,		DKW_PTYPE_ZFS },
 };
 
 static const char *
Index: sys/disk.h
===================================================================
RCS file: /cvsroot/src/sys/sys/disk.h,v
retrieving revision 1.75
diff -u -r1.75 disk.h
--- sys/disk.h	2 Mar 2020 16:01:56 -0000	1.75
+++ sys/disk.h	29 Mar 2020 07:56:13 -0000
@@ -211,6 +211,7 @@
 #define	DKW_PTYPE_VMKCORE	"vmkcore"
 #define	DKW_PTYPE_VMFS		"vmfs"
 #define	DKW_PTYPE_VMWRESV	"vmwresv"
+#define	DKW_PTYPE_ZFS		"zfs"
 
 /*
  * Ensure each symbol used in FSTYPE_DEFN in <sys/disklabel.h>