avcodec/mips/Makefile: Build fmtconvert_mips only if CONFIG_FMTCONVERT is set

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/mips/Makefile

@@ -10,7 +10,7 @@ MIPSFPU-OBJS-$(CONFIG_AMRWB_DECODER)      += mips/acelp_filters_mips.o     \
 MIPSFPU-OBJS-$(CONFIG_MPEGAUDIODSP)       += mips/mpegaudiodsp_mips_float.o
 MIPSDSPR1-OBJS-$(CONFIG_MPEGAUDIODSP)     += mips/mpegaudiodsp_mips_fixed.o
 MIPSFPU-OBJS-$(CONFIG_FFT)                += mips/fft_mips.o
-MIPSFPU-OBJS                              += mips/fmtconvert_mips.o
+MIPSFPU-OBJS-$(CONFIG_FMTCONVERT)         += mips/fmtconvert_mips.o
 OBJS-$(CONFIG_AC3DSP)                     += mips/ac3dsp_mips.o
 OBJS-$(CONFIG_AAC_DECODER)                += mips/aacdec_mips.o            \
                                              mips/aacsbr_mips.o            \