arm64: zynqmp: Do not clear reset reason

There is no need to clear reset reason register because it is protected by
PMUFW already which is reported when verbose log is enabled as:
pm_core.c@733 APU> No write permission to 0xFF5E0220

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
index a216eeb..6babc0eb 100644
--- a/board/xilinx/zynqmp/zynqmp.c
+++ b/board/xilinx/zynqmp/zynqmp.c
@@ -496,11 +496,7 @@
 
 	env_set("reset_reason", reason);
 
-	ret = zynqmp_mmio_write((ulong)&crlapb_base->reset_reason, ~0, ~0);
-	if (ret)
-		return -EINVAL;
-
-	return ret;
+	return 0;
 }
 
 static int set_fdtfile(void)