Revert "Remove the no longer used PV software aac decoder."

This reverts commit 1f8834711f23f66d528aca98cca9602fb18cab66.

Conflicts:

	media/libstagefright/codecs/aacdec/Android.mk

Change-Id: I32347bb08d5b04b7e3068329a2ebfd497fd085cf

av: Don't use fraunhofer for ARMv6 devices

Using fraunhofer on ARMv6 devices does not work - it causes a sigsev. Don't use it if ARMv7A is not present

Change-Id: I67e200ac2c1ab17a5c051fc5bc735ed7b1e5f21f

Fix build