remove extra arch-dep copies of fpi files

Reference: /n/atom/patch/applied/nixnofpi
Date: Thu Jun 12 15:32:52 CES 2014
Signed-off-by: quanstro@quanstro.net

# rm /sys/src/nix/bcm/fpi.c
# rm /sys/src/nix/bcm/fpi.h
# rm /sys/src/nix/bcm/fpimem.c
# rm /sys/src/nix/omap/fpi.c
# rm /sys/src/nix/omap/fpi.h
# rm /sys/src/nix/omap/fpimem.c