ARM: dts: da850-evm: add chosen and SPI alias

This patch will add the chosen container to point stdout-path to serial2
and set the alias for spi0 to spi1 since the SPI NOR flash exists on SPI1.

Suggested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>