The Flash parameters and settings are now stored in 'struct spi_nor'.
Use this instead of the stack allocated params.
Few functions stop passing pointer to params, as they can get it from
'struct spi_nor'. spi_nor_parse_sfdp() and children will keep passing
pointer to params because of the roll-back mechanism: in case the
parsing of SFDP fails, the legacy flash parameter and settings will be
restored.
Zeroing params is no longer needed because all SPI NOR users kzalloc
'struct spi_nor'.