davinci: da850: remove unused uart pinmux arrays.

The da850 uart pinmux arrays are not used.  Remove them.

Signed-off-by: Michael Williamson <michael.williamson@criticallink.com>
Tested-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>