Revert "cbfstool: Add 'hashcbfs' command to compute hash of CBFS region."

This reverts commit 272a1f05b9.

In Chrome OS this command's usage was dropped in favor of another
solution. As it's not used drop the support for it.

Change-Id: I58b51446d3a8b5fed7fc391025225fbe38ffc007
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/14261
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

util/cbfstool/Makefile.inc

@@ -2,7 +2,6 @@ cbfsobj :=
 cbfsobj += cbfstool.o
 cbfsobj += common.o
 cbfsobj += compress.o
-cbfsobj += cbfs_hash.o
 cbfsobj += cbfs_image.o
 cbfsobj += cbfs-mkstage.o
 cbfsobj += cbfs-mkpayload.o