x86: ivybridge: Set up EHCI USB

Add init for EHCI so that USB can be used.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/ivybridge/Makefile b/arch/x86/cpu/ivybridge/Makefile
index c6342cd..4a00757 100644
--- a/arch/x86/cpu/ivybridge/Makefile
+++ b/arch/x86/cpu/ivybridge/Makefile
@@ -17,3 +17,4 @@
 obj-y += report_platform.o
 obj-y += sata.o
 obj-y += sdram.o
+obj-y += usb_ehci.o