pulseaudio: fix non-NEON ARM compiles

pulseaudio: fix non-NEON ARM compiles

PulseAudio in some cases does not detect the ARM CPU's capabilities
correctly and enables NEON ASM while it is not supported. For example
when compiling for arm_arm1176jzf-s_vfp the assembler rejects this and
the compile fails:

{standard input}: Assembler messages:
{standard input}:27: Error: selected processor does not support `vld1.16 {d0},[r1]!' in ARM mode
{standard input}:28: Error: selected processor does not support `vmovl.s16 q0,d0' in ARM mode
{standard input}:29: Error: selected FPU does not support instruction -- `vcvt.f32.s32 q0,q0,#15'
{standard input}:31: Error: selected processor does not support `vst1.32 {q0},[r2]!' in ARM mode
{standard input}:70: Error: selected processor does not support `vld1.32 {q0},[r1]!' in ARM mode
{standard input}:71: Error: selected FPU does not support instruction -- `vcvt.s32.f32 q0,q0,#31'
{standard input}:72: Error: selected processor does not support `vqrshrn.s32 d0,q0,#16' in ARM mode
{standard input}:74: Error: selected processor does not support `vst1.16 {d0},[r2]!' in ARM mode
Makefile:8668: recipe for target 'pulsecore/libpulsecore_sconv_neon_la-sconv_neon.lo' failed

To fix this tell PulseAudio explicitly when to use the NEON ASM and when
not to.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>