doc: release: 4.4: deprecate CONFIG_XOPEN_STREAMS (again)

Deprecate the CONFIG_XOPEN_STREAMS Kconfig option in favour of
CONFIG_XSI_STREAMS, which matches the naming conventions of other XSI
Kconfig options and the actual Option Group name in the specification.

Please use CONFIG_XSI_STREAMS instead.

Note: this option was originally deprecated prior to 4.3.

Signed-off-by: Chris Friedt <chris@fr4.co>

Author: cfriedt

doc/releases/release-notes-4.4.rst

@@ -85,6 +85,10 @@ Deprecated APIs and options
       :c:member:`bt_conn_le_info.interval_us` instead. Note that the units have changed:
       ``interval`` was in units of 1.25 milliseconds, while ``interval_us`` is in microseconds.
 
+* POSIX
+
+  * :kconfig:option:`CONFIG_XOPEN_STREAMS` was deprecated. Instead, use :kconfig:option:`CONFIG_XSI_STREAMS`
+
 * Sensors
 
   * NXP