spi: offload: check for match callback when a trigger is being registered

Make match a required callback when a new trigger is being registered,
this allows that other functions like spi_offload_trigger_get() could
safely invoke the callback when it is required

In v2:
- improve readability of the condition

Signed-off-by: Andres Urian Florez <[email protected]>
Reviewed-by: David Lechner <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: andres-emb

drivers/spi/spi-offload.c

@@ -434,7 +434,7 @@ int devm_spi_offload_trigger_register(struct device *dev,
 {
 	struct spi_offload_trigger *trigger;
 
-	if (!info->fwnode || !info->ops)
+	if (!info->fwnode || !info->ops || !info->ops->match)
 		return -EINVAL;
 
 	trigger = kzalloc(sizeof(*trigger), GFP_KERNEL);