dma: mv_xor: Silence a bunch of LPAE-related warnings

Enabling some of the mvebu platforms in the multiplatform config for ARM
enabled these drivers, which also triggered a bunch of warnings when LPAE
is enabled (thus making phys_addr_t 64-bit).

Most changes are switching printk formats, but also a bit of changes to what
used to be array-based pointer arithmetic that could just be done with the
address types instead.

The warnings were:

drivers/dma/mv_xor.c: In function 'mv_xor_tx_submit':
drivers/dma/mv_xor.c:500:3: warning: format '%x' expects argument of type
    'unsigned int', but argument 4 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c: In function 'mv_xor_alloc_chan_resources':
drivers/dma/mv_xor.c:553:13: warning: cast to pointer from integer of
    different size [-Wint-to-pointer-cast]
drivers/dma/mv_xor.c:555:4: warning: cast from pointer to integer of
    different size [-Wpointer-to-int-cast]
drivers/dma/mv_xor.c: In function 'mv_xor_prep_dma_memcpy':
drivers/dma/mv_xor.c:584:2: warning: format '%x' expects argument of type
    'unsigned int', but argument 5 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c:584:2: warning: format '%x' expects argument of type
    'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c: In function 'mv_xor_prep_dma_xor':
drivers/dma/mv_xor.c:628:2: warning: format '%u' expects argument of type
    'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat]

Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Olof Johansson <olof@lixom.net>