cfi_flash: enable M18 flash chips family support.

Added new command set ID. Buffered write command processing is changed
in order to support M18 flash chips family.

Signed-off-by: Alexey Korolev <akorolev@infradead.org>
Signed-off-by: Vasiliy Leonenko <vasiliy.leonenko@mail.ru>
1 file changed