[build] Fix DEBUG builds for filenames with hyphens
Debug builds for filenames with hyphens such as:
$ make bin/via-rhine.dsk DEBUG=via-rhine
fail with:
[BUILD] bin/via-rhine.dbg1.o
<command-line>: error: missing whitespace after the macro name
make: *** [bin/via-rhine.dbg1.o] Error 1
This is because "-" is not a legal character in C identifiers, and
gcc rejects "-Ddebug_via-rhine=1" as an argument.
Signed-off-by: Daniel Verkamp <daniel@drv.nu>
Signed-off-by: Joshua Oreman <oremanj@rwcr.net>
Signed-off-by: Marty Connor <mdc@etherboot.org>