meta-phosphor: phosphor-debug-collector: Add symlink as git

Add a symbolic link to phosphor-debug-collector.bb named _git.bb and sets the
preferred version for the recipe.

(From meta-phosphor rev: 87491e53e44a00d3eb85883091213a43df43fca6)

Change-Id: I7d23561f7e13879e7e1fc896a10d950bb68f44c4
Signed-off-by: Patrick Venture <venture@google.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/conf/distro/include/phosphor-defaults.inc b/meta-phosphor/conf/distro/include/phosphor-defaults.inc
index 72fab7b..764a62d 100644
--- a/meta-phosphor/conf/distro/include/phosphor-defaults.inc
+++ b/meta-phosphor/conf/distro/include/phosphor-defaults.inc
@@ -252,3 +252,4 @@
 PREFERRED_VERSION_phosphor-ipmi-host = "1.0"
 PREFERRED_VERSION_phosphor-dbus-monitor = "1.0"
 PREFERRED_VERSION_mboxd = "1.0"
+PREFERRED_VERSION_phosphor-debug-collector = "1.0"