build: support configure in autogen.sh

 * enable libcl by default in configure.ac
 * specify parameters for autogen e.g.
   $ ./autogen.sh --prefix=/usr --enable-3alib --enable-aiq \
     --enable-gst --enable-drm --enable-libcl --enable-profiling \
     --enable-smartlib --enable-opencv

Signed-off-by: Wind Yuan <feng.yuan@intel.com>
diff --git a/configure.ac b/configure.ac
index 002bf76..9134f0f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -56,8 +56,8 @@
 
 AC_ARG_ENABLE(libcl,
     AS_HELP_STRING([--enable-libcl],
-                   [enable libcl image processor, @<:@default=no@:>@]),
-    [], [enable_libcl="no"])
+                   [enable libcl image processor, @<:@default=yes@:>@]),
+    [], [enable_libcl="yes"])
 
 AC_ARG_ENABLE(opencv,
     AS_HELP_STRING([--enable-opencv],