package/ruby: fix build on mips

Fixes:
 - http://autobuild.buildroot.org/results/d0ab5334f195a400a6d6dd6c49e3c1a2001b2b70

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/ruby/ruby.mk

@@ -48,6 +48,12 @@ endif
 ifeq ($(BR2_PACKAGE_BERKELEYDB),y)
 RUBY_DEPENDENCIES += berkeleydb
 endif
+ifeq ($(BR2_PACKAGE_LIBFFI),y)
+RUBY_DEPENDENCIES += libffi
+else
+# Disable fiddle to avoid a build failure with bundled-libffi on MIPS
+RUBY_CONF_OPTS += --with-out-ext=fiddle
+endif
 ifeq ($(BR2_PACKAGE_GDBM),y)
 RUBY_DEPENDENCIES += gdbm
 endif