components/boot, teams/server: Add partitioning hack for the Raspberry Pi 3

The Raspberry Pi 3 does not recognize a FAT filesystem marked with
the 0xef type, so until we drop support for this device, hack the
partition manually to use a legacy FAT filesystem partition type.

editbootinstall_rpilegacy.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+set -euxo pipefail
+
+diskname=$1
+devname="$2"
+loopname="${devname%*p?}"
+loopdev=/dev/${loopname#/dev/*}
+
+#==========================================
+# Force the ESP to use legacy MBR identifier
+#------------------------------------------
+#
+# Raspberry Pi 3 and older systems don't handle
+# the 0xef partition type for the ESP, so switch
+# to the legacy one.
+#
+sfdisk --change-id ${loopdev} 1 6