dmaengine: qcom_hidma: hide MSI handler when unused

The newly added MSI support causes a harmless warning when MSI
is disabled:

drivers/dma/qcom/hidma.c:558:20: error: 'hidma_chirq_handler_msi' defined but not used [-Werror=unused-function]

This adds another #ifdef to match that around the users of the function.

Fixes: 1c0e3e82a7fb ("dmaengine: qcom_hidma: add MSI support for interrupts")
Signed-off-by: Arnd Bergmann <[e-mail]>
Acked-by: Sinan Kaya <[e-mail]>
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/qcom/hidma.c

···
 	return hidma_ll_inthandler(chirq, lldev);
 }
 
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
 static irqreturn_t hidma_chirq_handler_msi(int chirq, void *arg)
 {
 	struct hidma_lldev **lldevp = arg;
···
 	return hidma_ll_inthandler_msi(chirq, *lldevp,
 				       1 << (chirq - dmadev->msi_virqbase));
 }
+#endif
 
 static ssize_t hidma_show_values(struct device *dev,
 				 struct device_attribute *attr, char *buf)