ionic: Query FW when getting VF info via ndo_get_vf_config

ionic: Query FW when getting VF info via ndo_get_vf_config

Currently when an administrator configures a VF via ndo_set_vf*,
the driver will send the set command to FW and then update the
cached value.  The cached value is then used when reporting
VF info via ndo_get_vf_config.

A problem is that the VF info may have been updated between
the last ndo_set_vf* and ndo_get_vf_info commands via some
other method, i.e. a VF changes its MAC address (assuming it's
allowed to do so) and since this is all managed by the FW,
this new value won't be reflected in the PF's cache of values.

To fix this, update the driver to always get the latest VF
information by making use of the IONIC_CMD_VF_GETATTR dev
command. The FW may not support getting all the attributes for
IONIC_CMD_VF_GETATTR, so the driver will only update the cached
VF config members if their associated IONIC_CMD_VF_GETATTR
was successful. Otherwise the cached VF config members will
remain the same as what was set in ndo_set_vf*.

Fixes: fbb39807e9ae ("ionic: support sr-iov operations")
Signed-off-by: Brett Creeley <brett@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>