uboot-imx

85xx: separate PIXIS virtual from physical address

Added a PIXIS_BASE_PHYS for use as the physical address and maintain
PIXIS_BASE as the virtual address of the PIXIS fpga registers.

This allows us to deal with 36-bit phys on these boards in the future.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Andy Fleming <afleming@freescale.com>