ocxl: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style
in header files for Open Coherent Accelerator (OCXL) compatible device
drivers. For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46

.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/20190920161826.GA6894@nishad


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