dropbear 2011.54 bbappend: switch to PRINC to work around a bug in bb.utils.vercmp:

| ERROR: Package version for package dropbear-dbg went backwards which would break package feeds from (0:2011.54-r0 to 0:2011.54-r0.meta-oe.1)

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>