migrate_localcount.bbclass: use PRAUTOINX instead of PN & PV

- we need to use PRAUTOINX (it covers all cases)
- it addresses bumped PE issues

[YOCTO #3071]

Signed-off-by: Constantin Musca <constantinx.musca@intel.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>