package infra: fix versioned patches for host packages

Without this patch we'd need separate versioned patch directories for
target and host packages, thus having unwanted duplication.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>