hv: clean up function definitions in npk_log.h

seperate the function definitions into debug/release directories
to better distinguish debug/release libraries

Tracked-On: #861
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/release/npk_log.c

@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2018 Intel Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <hypervisor.h>
+
+void npk_log_setup(__unused struct hv_npk_log_param *param) {}
+void npk_log_write(__unused const char *buf, __unused size_t len) {}