libcec: not available on pure static builds

libcec needs libdl, so it cannot work on pure static builds.

Fixes:

  http://autobuild.buildroot.org/results/670/670ce46627daaa4ae9ecdb8ffb6f97d0574354d4/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libcec/Config.in

@@ -3,6 +3,7 @@ config BR2_PACKAGE_LIBCEC
 	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	depends on BR2_USE_WCHAR
+	depends on !BR2_PREFER_STATIC_LIB
 	help
 	  libcec allows you in combination with the right hardware to
 	  control your home theater devices with your TV remote
@@ -10,6 +11,6 @@ config BR2_PACKAGE_LIBCEC
 
 	  http://libcec.pulse-eight.com
 
-comment "libcec needs a toolchain w/ C++, wchar, threads"
+comment "libcec needs a toolchain w/ C++, wchar, threads, dynamic library"
 	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_TOOLCHAIN_HAS_THREADS || \
-		!BR2_USE_WCHAR
+		!BR2_USE_WCHAR || BR2_PREFER_STATIC_LIB