cbfstool: Don't assume compiler is gcc, and use $(CC)

Change-Id: I49feb5be885369fca10c8db31329e51d87031641
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4841
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
1 file changed