Switch to SPDX tags

[lategoodbye]

Most of the BCM2835/Raspberry Pi drivers doesn't use SPDX tags.

Current list:

./drivers/dma/bcm2835-dma.c
./drivers/mailbox/bcm2835-mailbox.c
./drivers/spi/spi-bcm2835.c
./drivers/spi/spi-bcm2835aux.c
./drivers/mmc/host/bcm2835.c
./drivers/pinctrl/bcm/pinctrl-bcm2835.c
./drivers/pwm/pwm-bcm2835.c
./drivers/clk/bcm/clk-bcm2835-aux.c
./drivers/clk/bcm/clk-bcm2835.c
./drivers/thermal/broadcom/bcm2835_thermal.c
./drivers/i2c/busses/i2c-bcm2835.c
./drivers/clocksource/bcm2835_timer.c
./drivers/irqchip/irq-bcm2835.c
./drivers/char/hw_random/bcm2835-rng.c
./arch/arm/mach-bcm/board_bcm2835.c
./sound/soc/bcm/bcm2835-i2s.c
./drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
./drivers/firmware/raspberrypi.c
./drivers/soc/bcm/raspberrypi-power.c

Notes: Do not forget the header files. Do not send a single for all changes, instead one for each topic.

[lategoodbye]

Here is the first version (without the panel driver): https://github.com/lategoodbye/rpi-zero/tree/bcm2835-spdx

[lategoodbye]

While we are at this, we should make sure that MODULE_LICENSE match SPDX identifier: GPL-2.0+ => GPL GPL-2.0 => GPL v2

[lategoodbye]

First patch series is out: https://marc.info/?l=linux-arm-kernel&m=154029287612664&w=2

[lategoodbye]

The first series has been applied, the second is here: https://marc.info/?l=linux-arm-kernel&m=154185962726576&w=2

[lategoodbye]

Most of these patches has been applied. So send a new version to address Mark Brown comments for spi and ASoC patches.