common/sfc_efx/base: check for MAE privilege

common/sfc_efx/base: check for MAE privilege

VFs can't control MAE, so it's important to override the general
MAE capability bit by taking MAE privilege into account. Reorder
the code slightly to have the privileges queried before datapath
capabilities are discovered and add required MAE privilege check.

Fixes: eb4e80085fae ("common/sfc_efx/base: indicate support for MAE")
Cc: stable@dpdk.org
Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>