mm: increase the count of dma_mmu_remap areas

Increase the count of mmu remap areas in dma_mmu_remap to provide the
space for the carveout region with fixup. Otherwise when configured
CMA areas touch MAX_CMA_AREAS, it results in undefined behaviour due to
last cma area encroaching into fixup area. This undefined behaviour is
because of the section mappings of the last cma, where we end up in 
using with out clearing it's PTE's.

Change-Id: Ibbb2557022e2b123338d80be317877c2dcf7b9f1
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>