x86: Enable LMB and RAMDISK_HIGH by default

These options are used by the image code. To allow us to use the generic
code more easily, define these for x86.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/config.h b/arch/x86/include/asm/config.h
index f06a15c..ff15828 100644
--- a/arch/x86/include/asm/config.h
+++ b/arch/x86/include/asm/config.h
@@ -8,4 +8,7 @@
 #define _ASM_CONFIG_H_
 
 #define CONFIG_SYS_GENERIC_BOARD
+#define CONFIG_LMB
+#define CONFIG_SYS_BOOT_RAMDISK_HIGH
+
 #endif