xtensa: move exception handling func to arch internal header

z_xtensa_dump_stack() and z_xtensa_exccause() are both arch
internal functions that should not be exposed in public API.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>

arch/xtensa/core/fatal.c

@@ -11,6 +11,9 @@
 #include <xtensa_backtrace.h>
 #include <zephyr/debug/coredump.h>
 #include <zephyr/arch/common/exc_handle.h>
+
+#include <xtensa_internal.h>
+
 #include <zephyr/logging/log.h>
 LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
 

arch/xtensa/core/xtensa_asm2.c

@@ -17,6 +17,8 @@
 #include <zsr.h>
 #include <zephyr/arch/common/exc_handle.h>
 
+#include <xtensa_internal.h>
+
 LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
 
 extern char xtensa_arch_except_epc[];

arch/xtensa/include/xtensa_internal.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2014 Wind River Systems, Inc.
+ * Copyright (c) 2016 Cadence Design Systems, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_ARCH_XTENSA_INCLUDE_XTENSA_INTERNAL_H_
+#define ZEPHYR_ARCH_XTENSA_INCLUDE_XTENSA_INTERNAL_H_
+
+void z_xtensa_dump_stack(const z_arch_esf_t *stack);
+char *z_xtensa_exccause(unsigned int cause_code);
+
+#endif /* ZEPHYR_ARCH_XTENSA_INCLUDE_XTENSA_INTERNAL_H_ */

include/zephyr/arch/xtensa/exception.h

@@ -27,9 +27,6 @@ extern "C" {
  */
 typedef int z_arch_esf_t;
 
-void z_xtensa_dump_stack(const z_arch_esf_t *stack);
-char *z_xtensa_exccause(unsigned int cause_code);
-
 #endif
 
 #ifdef __cplusplus