mailbox: arm_mhu: Match only if compatible is "arm,mhu"

Since we will be soon adding a separate driver based on this ARM MHU
driver to support doorbell mode, let us add explicit check to match
the default compatible for this driver. This is needed as the probe
and match reuses the AMBA device ids currently and don't have any
explicit compatible check.

Signed-off-by: Sudeep Holla <[e-mail]>
Signed-off-by: Jassi Brar <[e-mail]>

drivers/mailbox/arm_mhu.c

···
 	struct device *dev = &adev->dev;
 	int mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET};
 
+	if (!of_device_is_compatible(dev->of_node, "arm,mhu"))
+		return -ENODEV;
+
 	/* Allocate memory for device */
 	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
 	if (!mhu)