staging: fsl-dpaa2/eth: Change max number of Tx queues

We use DPAA2_ETH_MAX_TX_QUEUES to dimension the array holding
information on Tx queues. At most, we can have one queue per cpu.

Until now we used the NR_CPUS macro to set the upper limit on number
of Tx queues. However, the platforms that the DPAA2 Ethernet driver
supports have at most 16 cores, whereas NR_CPUS is Kconfigurable and
can be much higher.

Avoid allocating memory we'll never use, by setting
DPAA2_ETH_MAX_TX_QUEUES to 16. Same for DPAA2_ETH_MAX_DPCONS.

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>