When the driver starts the device, it enables all the necessary
interrupts. However interrupts associated to host rings are enabled by
default on all GEN2 devices (except for dh895x) even when SR-IOV is
active. Fix this behaviour by checking if data structures associated to
VFs have been allocated to determine whether to enable such interrupts
or not.

Since the logic for the fix is the same across GEN2 devices, replace
the function to be fixed (adf_enable_ints()) with a single one
(adf_gen2_enable_ints()) in the common GEN2 code in adf_gen2_hw_data.c.
Likewise, remove the unnecessary duplication of defines too.
Signed-off-by: Marco Chiappero <marco.chiappero@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>