uboot-phytec

bootvx: x86: Assign bootaddr based on kernel memory base

On VxWorks x86 its bootline address is at a pre-defined offset @
0x1200. If 'bootaddr' is not passed via environment variable, we
assign its value based on the kernel memory base address.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>