i2c: davinci: bus recovery procedure to clear the bus

Come out of i2c time out condition by following the
bus recovery procedure outlined in the i2c protocol v3 spec.
The kernel must be robust enough to gracefully recover
from i2c bus failure without having to reset the machine.
This is done by first NACKing the slave, pulsing the SCL
line 9 times and then sending the stop command.

This patch has been tested on a DM6446 and DM355

Signed-off-by: Philby John <pjohn@in.mvista.com>
Signed-off-by: Srinivasan, Nageswari <nageswari@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>