php: readline needs dynamic library

Fixes:
http://autobuild.buildroot.net/results/604/604995ecf88e97976cbb9e4257ce85df66934ff3/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/php/Config.ext

@@ -15,8 +15,12 @@ config BR2_PACKAGE_PHP_EXT_OPCACHE
 	help
 	  Enable the Zend OPcache accelerator.
 
+comment "Readline needs a toolchain w/ dynamic library"
+	depends on BR2_STATIC_LIBS
+
 config BR2_PACKAGE_PHP_EXT_READLINE
 	bool "Readline"
+	depends on !BR2_STATIC_LIBS
 	select BR2_PACKAGE_NCURSES
 	select BR2_PACKAGE_READLINE
 	help