mtd: spi-nor-core: Add octal mode support

Add support for Octal flash devices. Octal flash devices use 8 IO lines
for data transfer. Currently only 1-1-8 Octal Read mode is supported.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
6 files changed