x86: Add initial video device init for Intel GMA

Intel's Graphics Media Accelerator (GMA) is a generic name for a wide range
of video devices. Add code to set up the hardware on ivybridge. Part of the
init happens in native code, part of it happens in a 16-bit option ROM for
those nostalgic for the 1970s.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/arch-ivybridge/bd82x6x.h b/arch/x86/include/asm/arch-ivybridge/bd82x6x.h
index 96d51c2..e1d9a9b 100644
--- a/arch/x86/include/asm/arch-ivybridge/bd82x6x.h
+++ b/arch/x86/include/asm/arch-ivybridge/bd82x6x.h
@@ -13,6 +13,8 @@
 void bd82x6x_usb_ehci_init(pci_dev_t dev);
 void bd82x6x_usb_xhci_init(pci_dev_t dev);
 int bd82x6x_init_pci_devices(void);
+int gma_func0_init(pci_dev_t dev, struct pci_controller *hose,
+		   const void *blob, int node);
 int bd82x6x_init(void);
 
 struct x86_cpu_priv;