ALSA: emu10k1: Add missing ifdef for emu->suspend reference

It's defined only for PM.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/emu10k1/emu10k1_main.c

@@ -714,8 +714,10 @@ static int emu1010_firmware_thread(void *data)
 		msleep_interruptible(1000);
 		if (kthread_should_stop())
 			break;
+#ifdef CONFIG_PM_SLEEP
 		if (emu->suspend)
 			continue;
+#endif
 		snd_emu1010_fpga_read(emu, EMU_HANA_IRQ_STATUS, &tmp); /* IRQ Status */
 		snd_emu1010_fpga_read(emu, EMU_HANA_OPTION_CARDS, &reg); /* OPTIONS: Which cards are attached to the EMU */
 		if (reg & EMU_HANA_OPTION_DOCK_OFFLINE) {