x86: quark: Enable the Memory Reference Code build

Turn on the Memory Reference code build in the quark Makefile.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/quark/Makefile

@@ -5,4 +5,5 @@
 #
 
 obj-y += car.o dram.o msg_port.o quark.o
+obj-y += mrc.o mrc_util.o hte.o smc.o
 obj-$(CONFIG_PCI) += pci.o