board: xilinx: Remove conditional check for Microblaze

U-Boot is not picking boot.scr script address from device tree
rather it's using default address for Microblaze platform,
and it's picking for other platforms. Remove conditional check
for Microblaze platform, so that u-boot pick up boot.scr script
address for all platforms from device tree.

Signed-off-by: Padmarao Begari <padmarao.begari@amd.com>
Link: https://lore.kernel.org/r/20240913093231.2343528-1-padmarao.begari@amd.com


Signed-off-by: Michal Simek <michal.simek@amd.com>