doc: announce deprecation of dpaa2 exposed mem structure
doc: announce deprecation of dpaa2 exposed mem structure

rte_dpaa2_memsegs is no more required once the dpaax (pa-va) translation
library has been introduced. This can be made internal (for fallback
operations) in subsequent release.

Signed-off-by: Shreyansh Jain <9744844f062a9f6cf95f66f06508da54c8fc7929@nxp.com>
Acked-by: Hemant Agrawal <90d96ef1ecd8ed49b97c7897be950e80824a9c5c@nxp.com>
Acked-by: Anatoly Burakov <814e00d8f6e4e81b7ccc7e3e5a0bfec0078f0203@intel.com>
Reviewed-by: Maxime Coquelin <9a2667dee3b90866bbc9c2696cff2b7d5616c95a@redhat.com>
Acked-by: Jerin Jacob <5bca7d2a432bc0f5422b70b2701a4e4fa32edd00@caviumnetworks.com>

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