cryptoo: bfin_crc - avoid get physical address of coherence memory by dma_map_single

cryptoo: bfin_crc - avoid get physical address of coherence memory by dma_map_single

- The 4-byte sg_mid_buf is located in the middle of the coherence memory
sg_cpu. Don't call dma_map_single to get its physical address. Get the its
base physical address from the physical address of sg_cpu instead.
- Should set up the dma descriptor data after the 4-byte sg_mid_buf is
filled in completely from next sg buffer.
- memory copy from sg buffer should be done via virtual address.
- Remove unused reference to blackfin header

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>