net: mvpp2: increase BM pool and RXQ size

BM pool and RXQ size increased to support Firmware Flow Control.
Minimum depletion thresholds to support FC are 1024 buffers.
BM pool size increased to 2048 to have some 1024 buffers
space between depletion thresholds and BM pool size.

Jumbo frames require a 9888B buffer, so memory requirements
for data buffers increased from 7MB to 24MB.

Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Acked-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>