x86: Make u-boot-x86.h a private header

Rather than including this arch-specific header file in common.h, include
it from within x86's u-boot.h header.

Also drop the comment about something to be fixed. It is not clear what
needs fixing.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/u-boot.h b/arch/x86/include/asm/u-boot.h
index 623771a..4c4527e 100644
--- a/arch/x86/include/asm/u-boot.h
+++ b/arch/x86/include/asm/u-boot.h
@@ -22,6 +22,7 @@
 
 /* Use the generic board which requires a unified bd_info */
 #include <asm-generic/u-boot.h>
+#include <asm/u-boot-x86.h>
 
 /* For image.h:image_check_target_arch() */
 #define IH_ARCH_DEFAULT IH_ARCH_I386
diff --git a/include/common.h b/include/common.h
index ffaed49..229ca4c 100644
--- a/include/common.h
+++ b/include/common.h
@@ -430,8 +430,8 @@
 # include <asm/setup.h>
 # include <asm/u-boot-arm.h>	/* ARM version to be fixed! */
 #endif /* CONFIG_ARM */
-#ifdef CONFIG_X86		/* x86 version to be fixed! */
-# include <asm/u-boot-x86.h>
+#ifdef CONFIG_X86
+# include <asm/u-boot.h>
 #endif /* CONFIG_X86 */
 #ifdef CONFIG_SANDBOX
 # include <asm/u-boot.h>