Currently, VF to PF interrupt handling is based on the DH895XCC device
behavior, which is not entirely common to all devices.

In order to make interrupt detection and handling correct for all of the
supported devices, make the interrupt handling device specific by:
 - introducing get_vf2pf_sources() for getting a 32 bits long value
   where each bit represents a vf2pf interrupt;
 - adding the device [enable|disable]_vf2pf_interrupts to hw_data;
 - defining [enable|disable]_vf2pf_interrupts for all the devices that
   are currently supported, using only their required and specific
   ERRSOU|ERRMASK registers (DH895XCC has 32 interrupts spread across
   ERRSOU3 and ERRSOU5, C62X/C3XXX has 16 in ERRSOU3 only, etc).
Code has been shared by different devices wherever possible.

This patch is based on earlier work done by Salvatore Benedetto.
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>