exynos: sandbox: ti: Add SPDX license identifiers and notes

exynos: sandbox: ti: Add SPDX license identifiers and notes

For some files I neglected to add a license. Rectify this:

arch/arm/dts/exynos4210-pinctrl-uboot.dtsi
arch/arm/dts/exynos4x12-pinctrl-uboot.dtsi
arch/arm/dts/exynos5250-pinctrl-uboot.dtsi
arch/arm/dts/exynos54xx-pinctrl-uboot.dtsi
arch/arm/dts/s5pc100-pinctrl.dtsi
arch/arm/dts/s5pc110-pinctrl.dtsi

This file came from Linux and has no license information there, so add a
comment to that effect:

arch/sandbox/include/asm/bitops.h

This file also came from Linux - presumably someone from TI could add the
license:

include/dt-bindings/pinctrl/omap.h

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Ingrid Viitanen <ingrid.viitanen@nokia.com>