ARM: davinci: da8xx-dt: Add spi0 lookup for clock matching

Add AUXDATA needed to match the device-tree node for spi0 to the
non-device-tree clock.

Signed-off-by: David Lechner <david@lechnology.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
[nsekhar@ti.com: commit description updates]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>