mtd: spinand: repeat reading in regular mode if continuous reading fails

mtd: spinand: repeat reading in regular mode if continuous reading fails

Continuous reading may result in multiple flash pages reading in one
operation. Unfortunately, not all spinand controllers support such
large reading. They will read less data. Unfortunately, the operation
can't be continued.

In this case:
 * disable continuous reading on this (not good enough) spi controller
 * repeat reading in regular mode.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>