package/util-linux: add missing SOB to patches

It is required that all patches in packages have the Signed-off-by of
the contributor who brought them into Buildroot.

Signed-off-by: Carlos Santos <unixmania@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/util-linux/0003-blkdiscard-use-O_EXCL-add-force.patch

@@ -8,6 +8,7 @@ unwanted discard on mounted device.
 
 Addresses: https://github.com/karelzak/util-linux/issues/915
 Signed-off-by: Karel Zak <kzak@redhat.com>
+Signed-off-by: Carlos Santos <unixmania@gmail.com>
 ---
  sys-utils/blkdiscard.8 |  5 +++++
  sys-utils/blkdiscard.c | 11 ++++++++---

package/util-linux/0004-libfdisk-add-fdisk_set_disklabel_id_from_string.patch

@@ -8,6 +8,7 @@ It's not comfortable if you want to avoid dialog or template.
 
 Addresses: https://github.com/karelzak/util-linux/issues/916
 Signed-off-by: Karel Zak <kzak@redhat.com>
+Signed-off-by: Carlos Santos <unixmania@gmail.com>
 ---
  libfdisk/docs/libfdisk-sections.txt |  1 +
  libfdisk/src/dos.c                  | 29 ++++++++++++++++++-----------

package/util-linux/0005-sfdisk-add-disk-id-to-change-disk-UUID-ID.patch

@@ -5,6 +5,7 @@ Subject: [PATCH] sfdisk: add --disk-id to change disk UUID/ID
 
 Addresses: https://github.com/karelzak/util-linux/issues/916
 Signed-off-by: Karel Zak <kzak@redhat.com>
+Signed-off-by: Carlos Santos <unixmania@gmail.com>
 ---
  disk-utils/sfdisk.8 |  5 +++++
  disk-utils/sfdisk.c | 54 +++++++++++++++++++++++++++++++++++++++++++++