davinci: am17x/da830/omap-l137 evm: setup NAND flash timing

davinci: am17x/da830/omap-l137 evm: setup NAND flash timing

Setup the NAND flash timings for DA830 EVM.

Before configuring the timing values, throughput calculation
using dd command yielded 477 kB/s write and 970 kB/s read speed.

After the timing configuration, the throughput was measured to
be 2.5 MB/s write and 5.1 MB/s read.

[Mukul Bhatnagar: actual calculation of timing values from the
NAND datasheet]

Signed-off-by: Sudhakar Rajashekhara <[email protected]>
Cc: Mukul Bhatnagar <[email protected]>
Signed-off-by: Sekhar Nori <[email protected]>
Acked-by: Kevin Hilman <[email protected]>
Signed-off-by: Kevin Hilman <[email protected]>