x86: Use unsigned long for address in table generation

We should use unsigned long rather than u32 for addresses. Update this so
that the table-generation code builds correctly on 64-bit machines.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/include/asm/sfi.h b/arch/x86/include/asm/sfi.h
index d1f0f0c..d6c44c9 100644
--- a/arch/x86/include/asm/sfi.h
+++ b/arch/x86/include/asm/sfi.h
@@ -132,6 +132,6 @@
  * @base:	Address to write table to
  * @return address to use for the next table
  */
-u32 write_sfi_table(u32 base);
+ulong write_sfi_table(ulong base);
 
 #endif /*_LINUX_SFI_H */