doc: services: portability: posix: add pthread_setcanceltype()

The function pthread_setcanceltype() is supported and mandatory
for conforming implementations.

Mark it as supported since the preceding commit.

Signed-off-by: Christopher Friedt <[email protected]>

Author: cfriedt

doc/services/portability/posix/option_groups/index.rst

@@ -61,7 +61,7 @@ multiple processes.
     pthread_once(),yes
     pthread_self(),yes
     pthread_setcancelstate(),yes
-    pthread_setcanceltype(),
+    pthread_setcanceltype(),yes
     pthread_setspecific(),yes
     pthread_sigmask(),
     pthread_testcancel(),