[spi_device] Hardcoded flash command values

[rivos-eblot]

Description

It seems that the RTL code defines common 25-series flash device commands twice as

• spi_flash_cmd_e in spi_cmdparse.sv, and
• spi_cmd_e in spi_deive_pkg.sv

However those definitions are not actually referenced elsewhere in the RTL code, and are only used in the DV files.

What only seem to matter for the SPI device implementation is the index/position of the command within the CMD_INFO registers, not there actual values that should be defined by the SW.

Maybe it's a left over from a previous implementation - or is it on purpose (?). It seems the definitions are duplicated anyway. It might be useful, i.e. help readability, to move these definitions where they are used (DV files) and only keep a single copy of them.