contrib: speexdsp: fix build with android-ndk10c

In android-ndk10c, there is a "arm_neon.h" for all archs. The arm_neon.h for
x86* contains correspondence between neon and sse. In speexdsp, There is a
conflict between resample_sse.h and resample_neon.h. So disable neon if arch is
known to don't have neon.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/speexdsp/rules.mak

@@ -27,6 +27,9 @@ ifeq ($(ARCH),aarch64)
 # old neon, not compatible with aarch64
 SPEEXDSP_CONF += --disable-neon
 endif
+ifndef HAVE_NEON
+SPEEXDSP_CONF += --disable-neon
+endif
 ifndef HAVE_FPU
 SPEEXDSP_CONF += --enable-fixed-point
 ifeq ($(ARCH),arm)