uboot-imx

x86: Don't build call64 and setjmp on 64-bit

These are currently not supported. Calling 64-bit code from 64-bit U-Boot is
much simpler, so this code is not needed. setjmp() is not yet implemented for
64-bit.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>