x86: apl: Support writing the IntelGraphicsMem table

This table is needed by the Linux graphics driver to handle graphics
correctly. Write it to ACPI.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/apollolake/Kconfig b/arch/x86/cpu/apollolake/Kconfig
index 16ac2b3..319f126 100644
--- a/arch/x86/cpu/apollolake/Kconfig
+++ b/arch/x86/cpu/apollolake/Kconfig
@@ -48,6 +48,7 @@
 	imply CMD_CLK
 	imply CLK_INTEL
 	imply ACPI_GPE
+	imply INTEL_GMA_ACPI
 
 if INTEL_APOLLOLAKE