ebuild: hack the chost check for armv7a-cros-linux-gnueabihf

We are in the process of rename armv7a-cros-linux-gnueabi to
armv7a-cros-linux-gnueabihf. See crbug.com/711369
We created two sets to toolchains, namely armv7a-cros-linux-gnueabi
and armv7a-cros-linux-gnueabihf, they are basically then same with
different names.
When changing the CHOST for one board from armv7a-cros-linux-gnueabi
to armv7a-cros-linux-gnueabihf, it failed on pre-cq. Because in the
build_package stage, it calls function VerifyBinpkg to verify that
an binary package exists for chromeos-chrome. The check requires the
CHOST from board configure and prebuilt packages are the same, and the
change broke that.
This patch silence the error to make pre-cq pass.

TEST=emerge-daisy -G zlib succeeded with new CHOST set.

Change-Id: I6ae231ebc663b2afc0c3773418258daa4f78d984
Reviewed-on: https://chromium-review.googlesource.com/1055211
Commit-Ready: Yunlian Jiang <yunlian@chromium.org>
Tested-by: Yunlian Jiang <yunlian@chromium.org>
Reviewed-by: Yunlian Jiang <yunlian@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/pym/portage/package/ebuild/config.py b/pym/portage/package/ebuild/config.py
index 45b7d08..18f478f 100644
--- a/pym/portage/package/ebuild/config.py
+++ b/pym/portage/package/ebuild/config.py
@@ -2154,6 +2154,9 @@
 					self._accept_chost_re = re.compile("^$")
 		pkg_chost = metadata.get('CHOST', '')
+		if pkg_chost in ('armv7a-cros-linux-gnueabi', 'armv7a-cros-linux-gnueabihf'):
+			return (self._accept_chost_re.match('armv7a-cros-linux-gnueabi') is not None or
+				self._accept_chost_re.match('armv7a-cros-linux-gnueabihf') is not None)
 		return not pkg_chost or \
 			self._accept_chost_re.match(pkg_chost) is not None