Add patch to make the port build with CMake 3.4.0.

In preparation for PR 204629, add a patch (also sent upstream) to make the
port build with CMake 3.4.0 by explicitly including a module used by the
build system.

devel/kdbg/files/patch-kdbg_CMakeLists.txt

@@ -0,0 +1,23 @@
+Required for building with CMake 3.4.0.
+
+Submitted via email directly to the upstream author.
+
+commit 2624465f87d7782527ee82567fd3a4fdf4c54241
+Author: Raphael Kubo da Costa <rakuco@FreeBSD.org>
+Date:   Thu Nov 26 11:58:11 2015 +0100
+
+    cmake: Explicitly include the CheckIncludeFiles module.
+
+    This fixes the build with CMake 3.4.0: kdbg/CMakeLists.txt was previously
+    relying on the module being included indirectly.
+
+--- kdbg/CMakeLists.txt
++++ kdbg/CMakeLists.txt
+@@ -4,6 +4,7 @@ add_subdirectory(typetables)
+ 
+ include_directories(${KDE4_INCLUDES} ${KDE4_INCLUDE_DIR} ${QT_INCLUDES} )
+ include(CheckFunctionExists)
++include(CheckIncludeFiles)
+ 
+ CHECK_INCLUDE_FILES(pty.h HAVE_PTY_H)
+ CHECK_INCLUDE_FILES(libutil.h HAVE_LIBUTIL_H)