Disable fpu using code when using clang/mips64 combo
it works around clang's inline asm error

error: couldn't allocate output register for constraint 'r'

Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>

--- a/libavcodec/mips/aacdec_mips.c
+++ b/libavcodec/mips/aacdec_mips.c
@@ -282,7 +282,7 @@ static void apply_ltp_mips(AACContext *a
     }
 }
 
-#if HAVE_MIPSFPU
+#if HAVE_MIPSFPU && !defined(__clang__)
 static av_always_inline void fmul_and_reverse(float *dst, const float *src0, const float *src1, int count)
 {
     /* Multiply 'count' floats in src0 by src1 and store the results in dst in reverse */
@@ -435,7 +435,7 @@ void ff_aacdec_init_mips(AACContext *c)
 #if HAVE_INLINE_ASM
     c->imdct_and_windowing         = imdct_and_windowing_mips;
     c->apply_ltp                   = apply_ltp_mips;
-#if HAVE_MIPSFPU
+#if HAVE_MIPSFPU && !defined(__clang__)
     c->update_ltp                  = update_ltp_mips;
 #endif /* HAVE_MIPSFPU */
 #endif /* HAVE_INLINE_ASM */