Not all SST devices implement the SST byte programming command.
Some devices (like SST25VF064C) implement only standard m25p80 page
write command.

Now SPI flash devices that need sst_write() are explicitly marked
with new SST_WRITE flag and the decision to use sst_write() is based
on this flag instead of manufacturer id.
Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>