re-enable BOARD_EGL_NEEDS_LEGACY_FB

Patches using it are coming.

Change-Id: Ic5a9e354055efc7aba600a0c1ad8bb66477008af
switch TARGET_QCOM_AUDIO_VARIANT to legacy

Change-Id: I8d7dfb4cb3761f1cf7090a456fe0920c0f0db28f