Refactor version handling logic for ADF_VF2PF_MSGTYPE_COMPAT_VER_REQ
and ADF_VF2PF_MSGTYPE_VERSION_REQ on the PF.
Response messages are now filled only after fully parsing the request,
in a consisted way with the rest of the PFVF codebase.

This patch also fixes a harmless double setting for VERSION in the
response for ADF_VF2PF_MSGTYPE_VERSION_REQ.
Signed-off-by: Marco Chiappero <marco.chiappero@intel.com>
Co-developed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>