More make dist fixes

Don't include the generated celt/arm/celt_pitch_xcorr_arm-gnu.S in the
dist tarball, but do include its celt_pitch_xcorr_arm.s source file.

Makefile.am

@@ -31,7 +31,7 @@ if CPU_ARM
 CELT_SOURCES += $(CELT_SOURCES_ARM)
 SILK_SOURCES += $(SILK_SOURCES_ARM)
 if OPUS_ARM_EXTERNAL_ASM
-CELT_SOURCES += $(CELT_SOURCES_ARM_ASM:.s=-gnu.S)
+nodist_libopus_la_SOURCES = $(CELT_SOURCES_ARM_ASM:.s=-gnu.S)
 BUILT_SOURCES = $(CELT_SOURCES_ARM_ASM:.s=-gnu.S) \
  $(CELT_AM_SOURCES_ARM_ASM:.s.in=.s) \
  $(CELT_AM_SOURCES_ARM_ASM:.s.in=-gnu.S)
@@ -122,6 +122,7 @@ EXTRA_DIST = version.mk \
              Makefile.unix \
              tests/run_vectors.sh \
              celt/arm/arm2gnu.pl \
+             celt/arm/celt_pitch_xcorr_arm.s \
              win32/VS2010/silk_float.vcxproj \
              win32/VS2010/celt.vcxproj.filters \
              win32/VS2010/opus.vcxproj \