s390: appldata: add SPDX identifiers to the remaining files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the arch/s390/appldata/ files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/appldata/appldata_base.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Base infrastructure for Linux-z/VM Monitor Stream, Stage 1.
  * Exports appldata_register_ops() and appldata_unregister_ops() for the

arch/s390/appldata/appldata_mem.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Data gathering module for Linux-VM Monitor Stream, Stage 1.
  * Collects data related to memory management.

arch/s390/appldata/appldata_net_sum.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Data gathering module for Linux-VM Monitor Stream, Stage 1.
  * Collects accumulated network statistics (Packets received/transmitted,

arch/s390/appldata/appldata_os.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Data gathering module for Linux-VM Monitor Stream, Stage 1.
  * Collects misc. OS related data (CPU utilization, running processes).