dropbear: Add patch for -c <command> option to dropbear

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/meta-phosphor/common/recipes-core/dropbear/dropbear_%.bbappend b/meta-phosphor/common/recipes-core/dropbear/dropbear_%.bbappend
index 36c0dcd..52a38bd 100644
--- a/meta-phosphor/common/recipes-core/dropbear/dropbear_%.bbappend
+++ b/meta-phosphor/common/recipes-core/dropbear/dropbear_%.bbappend
@@ -1,2 +1,3 @@
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
-SRC_URI += "file://dropbearkey.service"
+SRC_URI += "file://dropbearkey.service \
+	    file://0001-dropbear-Add-c-command-option-to-force-a-specific-co.patch"