crypto: marvell/cesa - use dma_addr_t for cur_dma

cur_dma is part of the software state, not read by the hardware.
Storing it in LE32 format is wrong, use dma_addr_t for this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>