x86: Tidy up VESA mode numbers

There are some bits which should be ignored when displaying the mode number.
Make sure that they are not included in the mode that is displayed.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/lib/bios.c

@@ -207,12 +207,14 @@ static u8 vbe_get_mode_info(struct vbe_mode_info *mi)
 
 static u8 vbe_set_mode(struct vbe_mode_info *mi)
 {
-	debug("VBE: Setting VESA mode %#04x\n", mi->video_mode);
+	int video_mode = mi->video_mode;
+
+	debug("VBE: Setting VESA mode %#04x\n", video_mode);
 	/* request linear framebuffer mode */
-	mi->video_mode |= (1 << 14);
+	video_mode |= (1 << 14);
 	/* don't clear the framebuffer, we do that later */
-	mi->video_mode |= (1 << 15);
-	realmode_interrupt(0x10, VESA_SET_MODE, mi->video_mode,
+	video_mode |= (1 << 15);
+	realmode_interrupt(0x10, VESA_SET_MODE, video_mode,
 			   0x0000, 0x0000, 0x0000, 0x0000);
 
 	return 0;
@@ -236,6 +238,7 @@ static void vbe_set_graphics(int vesa_mode, struct vbe_mode_info *mode_info)
 		return;
 	}
 
+	mode_info->video_mode &= 0x3ff;
 	vbe_set_mode(mode_info);
 }