doc-dst: parse-headers: highlight deprecated comments

When something is deprecated, highlight it, as we want it
to be clearer to the reader.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/sphinx/parse-headers.pl

@@ -196,6 +196,8 @@ $data =~ s/\n\s+\n/\n\n/g;
 #
 $data =~ s,([\_\`\*\<\>\&\\\\:\/]),\\$1,g;
 
+$data =~ s,DEPRECATED,**DEPRECATED**,g;
+
 #
 # Add references
 #