build-seed: add yosemite4

Meta will be adding the Yosemite4 platform to CI in the near
future.  Add it to the Jenkins build seed.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ifbd14e65cca24c55f7d1fcfaa4056f3652255fd2
diff --git a/jenkins/build-seed b/jenkins/build-seed
index 66fbf9e..f7d5338 100755
--- a/jenkins/build-seed
+++ b/jenkins/build-seed
@@ -36,6 +36,7 @@
     tiogapass
     witherspoon
     yosemitev2
+    yosemite4
     zaius
 )