bsp/arm: Broadcast cache maintenances
bsp/altera-vyclone-v: Broadcast cache maintenances
bsp/altera-cyclone-v: Enable L2 cache for network driver
bsp/altera-cyclone-v: Cache mbufs and clusters
bsp/altera-cyclone-v: Reduce size of nocache heap

Network mbufs and clusters now are cached. Thus the nocache heap can get reduced to 1 MByte.
bsp/altera-cyclone-v: Cleanup