Add the concept of a "repo test"

This commit adds a custom target called "repotest" to the build scripts,
which triggers tests to be run on the openbmc/openbmc repository.   It
attempts to call the script in meta-phosphor, being added in this
commit.   https://gerrit.openbmc-project.xyz/c/openbmc/openbmc/+/46743
Adding the custom target isn't the obvious approach, but considering
that the jenkins job is currently a multi-axis build, and we only want
to run this test once, it seemed like the best option, although I'm open
to alternatives.

This will need an update to add repotest to the jenkins axis before
these builds will start enforcing.

Tested:
Ran target=repotest ./build-setup.sh
and saw "Repo test passed" in the output.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I6caef6c28ee70f3c6194b9ea96cda8cfb58eb443
diff --git a/build-setup.sh b/build-setup.sh
index b1014d0..c05da98 100755
--- a/build-setup.sh
+++ b/build-setup.sh
@@ -40,6 +40,7 @@
 #                     Default: "latest"
 #  target             The target we aim to build.  Any system supported by
 #                     the openbmc/openbmc `setup` script is an option.
+#                     repotest is a target to specifically run the CI checks
 #                     Default: "qemuarm"
 #  no_tar             Set to true if you do not want the debug tar built
 #                     Default: "false"
@@ -136,6 +137,11 @@
   git clone https://github.com/openbmc/openbmc "${obmc_dir}"
 fi
 
+if [[ "$target" = repotest ]]; then
+  "${obmc_dir}"/meta-phosphor/scripts/run-repotest.sh
+  exit
+fi
+
 # Make and chown the xtrct_path directory to avoid permission errors
 if [ ! -d "${xtrct_path}" ]; then
   mkdir -p "${xtrct_path}"