boards: PineTime board skeleton

Pinout reference: http://files.pine64.org/doc/datasheet/pinetime/PineTime%20Port%20Assignment%20rev0.2.pdf
Adding PineTime SPI and I2C, some DTS and configuration definitions.
Adding led and button gpios.

Signed-off-by: Rafa Couto <caligari@treboada.net>
8 files changed