net: mvpp2: replace MVPP2_CPU_D_CACHE_LINE_SIZE with L1_CACHE_BYTES

The mvpp2 ip maybe used in SoCs which may have have 64bytes cacheline
size. Replace the MVPP2_CPU_D_CACHE_LINE_SIZE with L1_CACHE_BYTES.

And since dma_alloc_coherent() is always cacheline size aligned, so
remove the align checks.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>