Not sure if you're still looking for a solution, but the problem is in your command line
kgcc -DCARDBUS -DMODULE -D_KERNEL -Wall -Wstrict-prototypes -O6 -c dfe690.c dfe690_cb.o -I/usr/src/linux/pcmcia-cs-2.2.16/include/pcmcia
should be
kgcc -DCARDBUS -DMODULE -D_KERNEL -Wall -Wstrict-prototypes -O6 -c dfe690.c -o dfe690_cb.o -I/usr/src/linux/pcmcia-cs-2.2.16/include/pcmcia
You left out the '-o' that tells the compiler to make a module called dfe690_cb.o instead of one called dfe690.o.
HTH