Fix flac build on e500mc cores
This core does not have altivec, so we disable it in the build,
also reestablish the config option to enable/disable building
with altivec
If SPE is not detected we always build with altivec which is wrong. This
will check to make sure altivec is enabled and pass build options
through accordingly
(From OE-Core rev:
96241de59fdf548ae0f80cc9e4668f9ba11924ef)
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
