m68k: define syscall_get_arch()

syscall_get_arch() is required to be implemented on all architectures
in addition to already implemented syscall_get_nr(),
syscall_get_arguments(), syscall_get_error(), and
syscall_get_return_value() functions in order to extend the generic
ptrace API with PTRACE_GET_SYSCALL_INFO request.
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: Elvira Khabirova <lineprinter@altlinux.org>
Cc: Eugene Syromyatnikov <esyr@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-audit@redhat.com
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

arch/m68k/include/asm/syscall.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_M68K_SYSCALL_H
+#define _ASM_M68K_SYSCALL_H
+
+#include <uapi/linux/audit.h>
+
+static inline int syscall_get_arch(void)
+{
+	return AUDIT_ARCH_M68K;
+}
+
+#endif	/* _ASM_M68K_SYSCALL_H */