Alternative fix to disable autoconf run in cloog build

Another fix is here: https://android-review.googlesource.com/#/c/49393/

Change-Id: I7c041f5ee3c44282cfe7e3982eb65a2b7527b8a1
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>
TEST: Fix canadian build

1. Add new flags CFLAGS_FOR_BUILD and LDFLAGS_FOR_BUILD
   and use it for $BUILD_CC
   Similiar to https://android-review.googlesource.com/#/c/50032
2. unset LDFLAGS for cross-compile-build-tools
3. ARCH can be set by env. var.

Change-Id: I061aee782384ea14166043308490f31e48c6dd54

Conflicts:

	Makefile