staging: greybus: fix up SPDX comment in .h files

When these files originally got an SPDX tag, I used // instead of /* */
for the .h files.  Fix this up to use // properly.

Cc: Johan Hovold <johan@kernel.org>
Cc: greybus-dev@lists.linaro.org
Cc: devel@driverdev.osuosl.org
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NAlex Elder <elder@kernel.org>
Link: https://lore.kernel.org/r/20190825055429.18547-2-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/greybus/firmware.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus Firmware Management Header
  *

drivers/staging/greybus/gb-camera.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus Camera protocol driver.
  *

drivers/staging/greybus/gbphy.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus Bridged-Phy Bus driver
  *

drivers/staging/greybus/greybus.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus driver and device API
  *

drivers/staging/greybus/greybus_authentication.h

-// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
 /*
  * Greybus Component Authentication User Header
  *

drivers/staging/greybus/greybus_firmware.h

-// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
 /*
  * Greybus Firmware Management User Header
  *

drivers/staging/greybus/greybus_manifest.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus manifest definition
  *

drivers/staging/greybus/greybus_protocols.h

-// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
 /*
  * This file is provided under a dual BSD/GPLv2 license.  When using or
  * redistributing this file, you may do so under either license.

drivers/staging/greybus/greybus_trace.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus driver and device API
  *

drivers/staging/greybus/hd.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus Host Device
  *

drivers/staging/greybus/interface.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus Interface Block code
  *

drivers/staging/greybus/manifest.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus manifest parsing
  *

drivers/staging/greybus/module.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus Module code
  *

drivers/staging/greybus/operation.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus operations
  *

drivers/staging/greybus/spilib.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus SPI library header
  *

drivers/staging/greybus/svc.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Greybus SVC code
  *