lo: update man page since SCTP checksum offloading is supported

The loopback interface supports SCTP checksum offloading in
addition to TCP and UDP.
Reviewed by:		gbe
MFC after:		1 week
Differential Revision:	https://reviews.freebsd.org/D45698

share/man/man4/lo.4

@@ -27,7 +27,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd January 25, 2012
+.Dd June 23, 2024
 .Dt LO 4
 .Os
 .Sh NAME
@@ -55,11 +55,11 @@ be configured first unless no hardware
 interfaces exist.
 .Pp
 If the transmit checksum offload capability flag is enabled on a loopback
-interface, checksums will not be generated by IP, UDP, or TCP for packets
+interface, checksums will not be generated by IP, UDP, TCP, or SCTP for packets
 sent on the interface.
 .Pp
 If the receive checksum offload capability flag is enabled on a loopback
-interface, checksums will not be validated by IP, UDP, or TCP for packets
+interface, checksums will not be validated by IP, UDP, TCP, or SCTP for packets
 received on the interface.
 .Pp
 By default, both receive and transmit checksum flags will be enabled, in