ARM: davinci: Fix McASP mem resource names

The ASoC McASP driver looks for the mem resources by name
"mpu" and "dat" regions.
Change/add the needed name for the mem resources so the driver can pick the
correct resource.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>