net: eth: davinci_cpdma: 64-bit phys/dma_addr_t cleanup

Silences the below warnings when building with ARM_LPAE enabled, which
gives longer dma_addr_t by default:

drivers/net/ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create':
drivers/net/ethernet/ti/davinci_cpdma.c:182:3: warning: passing argument 3 of 'dma_alloc_attrs' from incompatible pointer type [enabled by default]
drivers/net/ethernet/ti/davinci_cpdma.c: In function 'desc_phys':
drivers/net/ethernet/ti/davinci_cpdma.c:222:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
drivers/net/ethernet/ti/davinci_cpdma.c:223:8: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: David S. Miller <davem@davemloft.net>