x86: Add chromebook_link board

This board is a 'bare' version of the existing 'link 'board. It does not
require coreboot to run, but is intended to start directly from the reset
vector.

This initial commit has place holders for a wide range of features. These
will be added in follow-on patches and series. So far it cannot be booted
as there is no ROM image produced, but it does build without errors.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0dba8ac..a5f24d0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -12,9 +12,32 @@
 
 config TARGET_COREBOOT
 	bool "Support coreboot"
+	help
+	  This target is used for running U-Boot on top of Coreboot. In
+	  this case Coreboot does the early inititalisation, and U-Boot
+	  takes over once the RAM, video and CPU are fully running.
+	  U-Boot is loaded as a fallback payload from Coreboot, in
+	  Coreboot terminology. This method was used for the Chromebook
+	  Pixel when launched.
+
+config TARGET_CHROMEBOOK_LINK
+	bool "Support Chromebook link"
+	help
+	  This is the Chromebook Pixel released in 2013. It uses an Intel
+	  i5 Ivybridge which is a die-shrink of Sandybridge, with 4GB of
+	  SDRAM. It has a Panther Point platform controller hub, PCIe
+	  WiFi and Bluetooth. It also includes a 720p webcam, USB SD
+	  reader, microphone and speakers, display port and 32GB SATA
+	  solid state drive. There is a Chrome OS EC connected on LPC,
+	  and it provides a 2560x1700 high resolution touch-enabled LCD
+	  display.
 
 endchoice
 
+source "arch/x86/cpu/ivybridge/Kconfig"
+
 source "board/chromebook-x86/coreboot/Kconfig"
 
+source "board/google/chromebook_link/Kconfig"
+
 endmenu