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

arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revA.dtso

@@ -5,9 +5,9 @@
  * (C) Copyright 2020 - 2021, Xilinx, Inc.
  *
  * SD level shifter:
- * "A" – A01 board un-modified (NXP)
- * "Y" – A01 board modified with legacy interposer (Nexperia)
- * "Z" – A01 board modified with Diode interposer
+ * "A" - A01 board un-modified (NXP)
+ * "Y" - A01 board modified with legacy interposer (Nexperia)
+ * "Z" - A01 board modified with Diode interposer
  *
  * Michal Simek <michal.simek@xilinx.com>
  */