arm: msm: smd: ifdef dsp irq handler

This irq handler isn't used in all cases, so add the proper ifdef. This
eliminates a compiler warning due to the function not getting used.
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>

arch/arm/mach-msm/smd.c

@@ -378,11 +378,13 @@ static irqreturn_t smd_modem_irq_handler(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+#if defined(CONFIG_QDSP6)
 static irqreturn_t smd_dsp_irq_handler(int irq, void *data)
 {
 	handle_smd_irq(&smd_ch_list_dsp, notify_dsp_smd);
 	return IRQ_HANDLED;
 }
+#endif
 
 static void smd_fake_irq_handler(unsigned long arg)
 {