MIPS: Enable HAVE_ARCH_TRACEHOOK.

This enables /proc/<pid>/syscall and the ptrace PTRACE_GETREGSET and
PTRACE_SETREGSET operations.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e70cf31..d523b54 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -8,6 +8,7 @@
 	select HAVE_PERF_EVENTS
 	select PERF_USE_VMALLOC
 	select HAVE_ARCH_KGDB
+	select HAVE_ARCH_TRACEHOOK
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_TRACE_MCOUNT_TEST