dma-mapping: Add dma_remap functions

After getting an allocation from dma_alloc_coherent, there
may be cases where it is necessary to remap the handle
into the CPU's address space (e.g. no CPU side mapping was
requested at allocation time but now one is needed). Add
APIs to bring a handle into the CPU address space again.

Change-Id: Ieb9231c5f24d45aeb7436f643c9b87b93871f85d
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
[lmark@codeaurora.org: fix additional call to dma_common_free_remap]
Signed-off-by: Liam Mark <lmark@codeaurora.org>