Flash device controller. The h/w card that actually
controls Flash read/write/erase. Relevant for the AGS+
systems where Flash may be controlled by the MC+, STR or
the ENVM cards, cards that may not actually contain the
Flash chips.
For systems that have removable PCMCIA flash cards that
are controlled by a PCMCIA controller chip, this object
may contain a description of that controller chip.
Where irrelevant (Flash is a direct memory mapped device
accessed directly by the main processor), this object will
have an empty (NULL) string.