moarvm: select libffi when building for MIPS

Otherwise the compilation will fail like this:

./libmoar.so: undefined reference to `dcCallbackThunkEntry'

See: https://github.com/MoarVM/MoarVM/issues/222

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/moarvm/Config.in

@@ -9,6 +9,9 @@ config BR2_PACKAGE_MOARVM
 	select BR2_PACKAGE_LIBUV
 	select BR2_PACKAGE_LIBTOMMATH
 	select BR2_PACKAGE_LIBATOMIC_OPS
+	# dyncall does not work on MIPS; libffi needs to be used.
+	# See: https://github.com/MoarVM/MoarVM/issues/222
+	select BR2_PACKAGE_LIBFFI if BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el
 	help
 	  Short for "Metamodel On A Runtime", MoarVM is a virtual machine
 	  built especially for Rakudo Perl 6 and the NQP Compiler Toolchain.