media: docs: make RC documents more compatible with Sphinx 3.1+

Sphinx 3.x broke support for the cdomain.py extension, as the
c domain code was rewritten. Due to that, the c tags need to
be re-written, in order to use the new c domain notation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/userspace-api/media/rc/lirc-read.rst

@@ -1,4 +1,5 @@
 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: RC
 
 .. _lirc-read:
 
@@ -11,7 +12,6 @@ Name
 
 lirc-read - Read from a LIRC device
 
-
 Synopsis
 ========
 
@@ -19,10 +19,7 @@ Synopsis
 
     #include <unistd.h>
 
-
 .. c:function:: ssize_t read( int fd, void *buf, size_t count )
-    :name: lirc-read
-
 
 Arguments
 =========
@@ -39,9 +36,9 @@ Arguments
 Description
 ===========
 
-:ref:`read() <lirc-read>` attempts to read up to ``count`` bytes from file
+:c:func:`read()` attempts to read up to ``count`` bytes from file
 descriptor ``fd`` into the buffer starting at ``buf``.  If ``count`` is zero,
-:ref:`read() <lirc-read>` returns zero and has no other results. If ``count``
+:c:func:`read()` returns zero and has no other results. If ``count``
 is greater than ``SSIZE_MAX``, the result is unspecified.
 
 The exact format of the data depends on what :ref:`lirc_modes` a driver
@@ -59,7 +56,6 @@ by hardware decoders. The :c:type:`rc_proto` member is set to the
 used for transmission, and ``scancode`` to the decoded scancode,
 and the ``keycode`` set to the keycode or ``KEY_RESERVED``.
 
-
 Return Value
 ============