Staging: kpc2000: kpc_dma: Use the SPDK comment style.

SPDK-License-Identifier comment should have this form
// SPDX-License-Identifier: <GPL-...>

Signed-off-by: Sam Muhammed <jane.pnx9@gmail.com>
Link: https://lore.kernel.org/r/7531e3e3fa7c046e93d2caaa6fa2e76c5c53f04d.1585143581.git.jane.pnx9@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>