arm: dma-mapping: map sg lists into the SMMU as virtually contiguous

Following commit implements mapping of sg virtually contiguously.

"arm64: dma-mapping: map sg lists into the SMMU as virtually
contiguous"
a03f74ef16cc73531795176d3ea8b82b66ed0146

This has been left for ARM (32-bit). Implement the same for ARM.

Change-Id: Ibf67f29a60b8d19e526c4719590f2f473ea9dca5
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>