This patch adds a flag to struct flash_info indicating that
fast_read is not supported. This now gives the following logic
when determing whether to enable fastread:

If the flash chip does not support fast_read, then disable it.
Otherwise:
1) enable fast_read if device node contains m25p,fast-read
2) enable fast_read if forced in Kconfig

This makes enabling CONFIG_M25PXX_USE_FAST_READ a safe option
since we no longer enable the fast_read option unconditionally.

For now fast_read is disabled for the everspin mr25h256 and the
catalyst devices. Others may need the flag aswell.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>