x86: Stop working around skip-at-start

With a recent Binman change, the skip-at-start property is now honoured,
meaning that all image-pos values in the affected section start from
the skip-at-start value.

The x86 code works around the old behaviour at present, so update it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/intel_common/intel_opregion.c b/arch/x86/cpu/intel_common/intel_opregion.c
index 78caff0..4a2717b 100644
--- a/arch/x86/cpu/intel_common/intel_opregion.c
+++ b/arch/x86/cpu/intel_common/intel_opregion.c
@@ -31,6 +31,7 @@
 	size = vbt.size;
 	if (size > sizeof(vbt_data))
 		return log_msg_ret("vbt", -E2BIG);
+	vbt.image_pos += CONFIG_ROM_SIZE;
 	ret = spi_flash_read_dm(dev, vbt.image_pos, size, vbt_data);
 	if (ret)
 		return log_msg_ret("read", ret);