treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

NFC: pn544: Add MEI physical layer

With the new mei_phy NFC driver API, the pn544 MEI physical layer is
minimal and similar to the microread one.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

NFC: pn544: Separate the core code and the i2c one into different modules

As we may need to support other physical layers, we can avoid linking the
core part into each and every pn544 module.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

NFC: Separate pn544 hci driver in HW dependant and independant parts

The driver now has all HCI stuff isolated in one file, and all the
hardware link specifics in another. Writing a pn544 driver on top of
another hardware link is now just a matter of adding a new file for that
new hardware specifics.

Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>