colibri-imx8x: update env memory layout

Update the distro config env memory layout for the Colibri iMX8X:

- kernel_comp_addr_r=0xb0000000 temporary area for uncompressing (ie FIT
images or Image.gz booted using booti)
- kernel_comp_size=0x08000000
- loadaddr=0x95400000 avoiding any reserved areas located before that
- fdt_addr_r = loadaddr + 128MB - allows for 128MB kernel
- scriptaddr = fdt_addr_r + 512KB - allows for 512KB fdt
- ramdisk_addr_r = scriptaddr + 512KB - allows for 512KB script

Idea of memory layout taken from commit a9f1e35b
("apalis-imx8: update env memory layout").

Note that for our regular BSP Layers and Reference Images for Yocto
Project an updated distro boot script is required (see
meta-toradex-bsp-common/recipes-bsp/u-boot/u-boot-distro-boot).

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@toradex.com>