This patch increases the MAX_MMAP_REGIONS build flag to allow
Tegra210 platforms to dynamically map multiple memory apertures
at the same time. This takes care of scenarios when we get multiple
requests to memmap memory apertures at the same time.

Change-Id: If4fe23b454e7d588e35acfbf024b9ccbb3daccc7
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>