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-get-send-mode.rst

@@ -1,4 +1,5 @@
 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: RC
 
 .. _lirc_get_send_mode:
 .. _lirc_set_send_mode:
@@ -15,11 +16,13 @@ LIRC_GET_SEND_MODE/LIRC_SET_SEND_MODE - Get/set current transmit mode.
 Synopsis
 ========
 
-.. c:function:: int ioctl( int fd, LIRC_GET_SEND_MODE, __u32 *mode )
-    :name: LIRC_GET_SEND_MODE
+.. c:macro:: LIRC_GET_SEND_MODE
 
-.. c:function:: int ioctl( int fd, LIRC_SET_SEND_MODE, __u32 *mode )
-    :name: LIRC_SET_SEND_MODE
+``int ioctl(int fd, LIRC_GET_SEND_MODE, __u32 *mode)``
+
+.. c:macro:: LIRC_SET_SEND_MODE
+
+``int ioctl(int fd, LIRC_SET_SEND_MODE, __u32 *mode)``
 
 Arguments
 =========
@@ -30,7 +33,6 @@ Arguments
 ``mode``
     The mode used for transmitting.
 
-
 Description
 ===========
 
@@ -44,14 +46,12 @@ modes the driver supports.
 Return Value
 ============
 
-
 .. tabularcolumns:: |p{2.5cm}|p{15.0cm}|
 
 .. flat-table::
     :header-rows:  0
     :stub-columns: 0
 
-
     -  .. row 1
 
        -  ``ENODEV``