x86: broadwell: Add an LPC driver

Add a driver for the broadwell LPC (low-pin-count peripheral). This mostly
uses common code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/broadwell/Makefile b/arch/x86/cpu/broadwell/Makefile
index 39bf733..3054a89 100644
--- a/arch/x86/cpu/broadwell/Makefile
+++ b/arch/x86/cpu/broadwell/Makefile
@@ -6,6 +6,7 @@
 
 obj-y += cpu.o
 obj-y += iobp.o
+obj-y += lpc.o
 obj-y += northbridge.o
 obj-y += pch.o
 obj-y += pinctrl_broadwell.o