The top half of the VF drivers handled only a source at the time.
If an interrupt for PF2VF and bundle occurred at the same time, the ISR
scheduled only the bottom half for PF2VF.
This patch fixes the VF top half so that if both sources of interrupt
trigger at the same time, both bottom halves are scheduled.

This patch is based on earlier work done by Conor McLoughlin.
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Marco Chiappero <marco.chiappero@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>