mtd: davinci: relax a timeout for ECC-initialization

Sudhakar found out that 100µs are enough. Sadly, his updated patch was
overlooked and an older version still using 100ms was merged. Fix this.

Reference: http://patchwork.ozlabs.org/patch/59180/



Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>