davinci: add spi devices on tnetv107x evm

This patch adds definitions for spi devices on the tnetv107x evm platform.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>