ssh: replace openssh with dropbear

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/classes/obmc-phosphor-image.bbclass b/classes/obmc-phosphor-image.bbclass
index 59be345..577e9f0 100644
--- a/classes/obmc-phosphor-image.bbclass
+++ b/classes/obmc-phosphor-image.bbclass
@@ -30,7 +30,7 @@
        obmc-phosphor-event-mgmt \
        obmc-phosphor-policy-mgmt \
        obmc-phosphor-system-mgmt \
-       ssh-server-openssh \
+       ssh-server-dropbear \
        "
 
 IMAGE_INSTALL += " \