The MIPS-specific source for vector scaling operations fails to build on
Debian's mips64el:
[97/303] Compiling C object webrtc/common_audio/libcommon_audio.a.p/signal_processing_vector_scaling_operations_mips.c.o
FAILED: webrtc/common_audio/libcommon_audio.a.p/signal_processing_vector_scaling_operations_mips.c.o
cc [...] webrtc/common_audio/libcommon_audio.a.p/signal_processing_vector_scaling_operations_mips.c.o.d -o webrtc/common_audio/libcommon_audio.a.p/signal_processing_vector_scaling_operations_mips.c.o -c ../webrtc/common_audio/signal_processing/vector_scaling_operations_mips.c
/tmp/cc7UGPkY.s: Assembler messages:
/tmp/cc7UGPkY.s:57: Error: opcode not supported on this processor: mips64r2 (mips64r2) `extrv_r.w $3,$ac0,$8'
ninja: build stopped: subcommand failed.
The EXTRV_R.W instruction it uses is part of DSP extensions for this
architecture. In signal_processing_library.h, this function's prototype
is guarded with #if defined(MIPS_DSP_R1_LE). Guard the implementation
like that as well to fix the error.
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>