arm64: zynqmp: Convert kv260-revA overlay to ASCII text

File was in UTF-8 format but there is no reason for it. Convert it to
ASCII/plain text.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/9161f4e1d449edd86e642b6769575b8e201fccf0.1684244418.git.michal.simek@amd.com