liquid-dsp: fix powerpc/altivec build failures

When a powerpc target is detected the build system tries to force
altivec support but that's wrong:

Not every powerpc processor has altivec instruction support.

It's using the removed/deprecated -faltivec compiler directive when it
should be using -maltivec instead.

Even if the above conditions are corrected the altivec codepath fails
to build properly.

So just disable altivec in general using the standard
--enable-simdoverride configure option. Fixes:

http://autobuild.buildroot.net/results/e1b/e1b6cf76a7a4ae754a928d211e779e9381198f48/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/liquid-dsp/liquid-dsp.mk

@@ -34,6 +34,11 @@ ifeq ($(BR2_PACKAGE_FFTW_PRECISION_SINGLE),y)
 LIQUID_DSP_LDFLAGS += -lfftw3f
 endif
 
+# disable altivec, it has build issues
+ifeq ($(BR2_powerpc)$(BR2_powerpc64),y)
+LIQUID_DSP_CONF_OPTS += --enable-simdoverride
+endif
+
 ifeq ($(BR2_PACKAGE_FFTW_PRECISION_DOUBLE),y)
 LIQUID_DSP_LDFLAGS += -lfftw3
 endif