bf60x: Add wake up latency bench for deep sleep mode.

Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBob Liu <lliubbo@gmail.com>

arch/blackfin/mach-bf609/dpm.S

@@ -105,6 +105,8 @@ ENTRY(_enter_deepsleep)
 	sti r0;
 	SSYNC;
 
+	bfin_init_pm_bench_cycles;
+
 	/* Fall into deep sleep in idle*/
 	idle;
 	SSYNC;