staging: Fix tnt4882 license to be SPDX compliant

"GPL-2" is not a valid SPDX license identifier[1].  Update to SPDX
compliant string "GPL-2.0-only".

[1] https://spdx.org/licenses

Signed-off-by: Prarit Bhargava <[email protected]>
Cc: Dave Penkler <[email protected]>
Cc: Rohit Chavan <[email protected]>
Signed-off-by: Prarit Bhargava <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: prarit

drivers/staging/gpib/tnt4882/mite.c

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2
+// SPDX-License-Identifier: GPL-2.0-only
 
 /*
  *	Hardware driver for NI Mite PCI interface chip,

drivers/staging/gpib/tnt4882/mite.h

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2 */
+/* SPDX-License-Identifier: GPL-2.0-only */
 
 /*
  *   Hardware driver for NI Mite PCI interface chip