For 64bit Architectures mmap() is equivalent to mmap64(). This patch
maps mmap64() to mmap() in a similar way to other syscalls that differ
based on the size of off_t and off64_t
Change-Id: If21b21ef71120bad23d9a608d02d4a7de5220a87
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>