dmaengine: idxd: fix opcap sysfs attribute output

The operation capability register is 256bits. The current output only
prints out the first 64bits. Fix to output the entire 256bits. The current
code omits operation caps from IAX devices.

Fixes: c52ca478 ("dmaengine: idxd: add configuration component of driver")
Reported-by: Lucas Van <lucas.van@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161645624963.2003736.829798666998490151.stgit@djiang5-desk3.ch.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/idxd/sysfs.c

@@ -1449,8 +1449,14 @@ static ssize_t op_cap_show(struct device *dev,
 {
 	struct idxd_device *idxd =
 		container_of(dev, struct idxd_device, conf_dev);
+	int i, rc = 0;
+
+	for (i = 0; i < 4; i++)
+		rc += sysfs_emit_at(buf, rc, "%#llx ", idxd->hw.opcap.bits[i]);
 
-	return sprintf(buf, "%#llx\n", idxd->hw.opcap.bits[0]);
+	rc--;
+	rc += sysfs_emit_at(buf, rc, "\n");
+	return rc;
 }
 static DEVICE_ATTR_RO(op_cap);