lua: use PV for generating Version in lua.pc

Lua was updated to 5.3.2, however lua.pc still has 5.2.2 listed as
Version in pkg-config metadata file. Instead of bumping the Version
field in lua.pc make sure that we are future proof and update the field
automatically with value of ${PV}.

Signed-off-by: Maciej Borzecki <maciej.borzecki@open-rnd.pl>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>