make: fix dependency problem

When building with a large "-j" value, the build could fail with a message like
    gcc -o mesaflash mesaflash.o libanyio.a -lpci -lm
    gcc: error: libanyio.a: No such file or directory
    Makefile:70: recipe for target 'mesaflash' failed
    make: *** [mesaflash] Error 1
make mesaflash explicitly depend on libanyio.a to avoid this.

Signed-off-by: Jeff Epler <jepler@unpythonic.net>