mtd: spi-nor: get rid of SPI_NOR_NO_FR

The Everspin FRAM devices are the only user of the NO_FR flag. Drop the
global flag and instead use a manufacturer fixup for the Everspin
flashes to drop the fast read support.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
[pratyush@kernel.org: s/evervision/everspin/g in code and commit message]
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Link: https://lore.kernel.org/r/20240419141249.609534-5-mwalle@kernel.org