Unreliable/Slow Flashing with 2MiB Chips

[nullproem]

Flashing 2MiB chips (SST49LF016C) is nearly impossible due to how slowly the firmware communicates with the flash chip. In the one(!) successful flash of this chip it took 1hr46s and all other attempts hung at some point and never completed. As it stands, this firmware is only useful for chips <2MiB in size.

Note that flashing the SST49LF016C with flashrom requires modification to its source due to an incorrect setting of the bus type but reading/erasing seems to work fine afterward.