doc-rst: FE_DISHNETWORK_SEND_LEGACY_CMD: improve man-like format

Parsing this file were causing lots of warnings with sphinx,
due to the c function prototypes.

Fix that by prepending them with .. c:function::

While here, use the same way we document man-like pages,
at the V4L side of the book and add escapes to asterisks.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/linux_tv/media/dvb/FE_DISHNETWORK_SEND_LEGACY_CMD.rst

@@ -6,7 +6,8 @@
 FE_DISHNETWORK_SEND_LEGACY_CMD
 ******************************
 
-DESCRIPTION
+Description
+-----------
 
 WARNING: This is a very obscure legacy command, used only at stv0299
 driver. Should not be used on newer drivers.
@@ -17,13 +18,13 @@ frontend, for Dish Network legacy switches.
 As support for this ioctl were added in 2004, this means that such
 dishes were already legacy in 2004.
 
-SYNOPSIS
+Synopsis
+--------
 
-int ioctl(int fd, int request =
-:ref:`FE_DISHNETWORK_SEND_LEGACY_CMD`,
-unsigned long cmd);
+.. c:function:: int  ioctl(int fd, int request = FE_DISHNETWORK_SEND_LEGACY_CMD, unsigned long cmd)
 
-PARAMETERS
+Arguments
+----------
 
 
 
@@ -39,7 +40,8 @@ PARAMETERS
        -  sends the specified raw cmd to the dish via DISEqC.
 
 
-RETURN VALUE
+Return Value
+------------
 
 On success 0 is returned, on error -1 and the ``errno`` variable is set
 appropriately. The generic error codes are described at the