arm64/stacktrace: Export save_stack_trace_regs()

The ARM64 implements the save_stack_trace_regs function, but it is
unusable for any diagnostic tooling compiled as a kernel module due
the missing EXPORT_SYMBOL_GPL for the function.  Export
save_stack_trace_regs() to align with other architectures such as
s390, openrisc, and powerpc. This is similar to the ARM64 export of
save_stack_trace_tsk() added in git commit e27c7fa0.
Signed-off-by: NWilliam Cohen <wcohen@redhat.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/stacktrace.c

@@ -143,6 +143,7 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
 	if (trace->nr_entries < trace->max_entries)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
+EXPORT_SYMBOL_GPL(save_stack_trace_regs);
 
 static noinline void __save_stack_trace(struct task_struct *tsk,
 	struct stack_trace *trace, unsigned int nosched)