avcodec/Makefile: Correct name of cbd2_dpcm decoder

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/Makefile

@@ -285,7 +285,7 @@ OBJS-$(CONFIG_BRENDER_PIX_DECODER)     += brenderpix.o
 OBJS-$(CONFIG_C93_DECODER)             += c93.o
 OBJS-$(CONFIG_CAVS_DECODER)            += cavs.o cavsdec.o cavsdsp.o \
                                           cavsdata.o
-OBJS-$(CONFIG_CBD2_DECODER)            += dpcm.o
+OBJS-$(CONFIG_CBD2_DPCM_DECODER)       += dpcm.o
 OBJS-$(CONFIG_CCAPTION_DECODER)        += ccaption_dec.o ass.o
 OBJS-$(CONFIG_CDGRAPHICS_DECODER)      += cdgraphics.o
 OBJS-$(CONFIG_CDTOONS_DECODER)         += cdtoons.o