test/eal: add cases for in-memory and single-file-segments

test/eal: add cases for in-memory and single-file-segments

Added unit test case for eal command line '--in-memory' option
which will cover below functions.
get_seg_memfd()
test_memfd_create()
pagesz_flags()

Added unit test case for eal command line '--single-file-segments' option
which will cover resize_hugefile().

Signed-off-by: Pallantla Poornima <pallantlax.poornima@intel.com>
Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>