xfsprogs: Add ability to cross compile to ARM.

Add BUILD_CFLAGS variable, allowing cross compilation.
[http://oss.sgi.com/archives/xfs/2016-02/msg00033.html]

Add BUILD_CC to be able to set the host compiler as well.

BUG=chromium:347322
TEST=Compile, deploy on veyron_speedy.

Change-Id: I6ec3c2a82465c4ee3087aeda5f29ff9176a99721
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/347745
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed