cbfstool/Makefile*: Use `LDFLAGS` instead of `LINKFLAGS`

Commit 0e53931f (cbfstool: Clean up in preparation for adding new
files) split out the flags and introduced the variable `LINKFLAGS`.
Rename it to `LDFLAGS` which is more commonly used.

Change-Id: Ib6299f8ef5cf30dbe05bfae36f30ae4371f0a738
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-on: http://review.coreboot.org/10064
Tested-by: build bot (Jenkins)
Reviewed-by: Sol Boucher <solb@chromium.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2 files changed