multimedia/mswebrtc: Fix build on aarch64.

multimedia/mswebrtc/files/patch-CMakeLists.txt

@@ -1,16 +1,30 @@
 i386 target on BSDs doesn't include SSE2 by default
 
---- CMakeLists.txt.orig	2017-07-20 13:56:58 UTC
+--- CMakeLists.txt.orig	2017-07-20 15:56:58 UTC
 +++ CMakeLists.txt
-@@ -204,6 +204,11 @@ if(ENABLE_AEC)
+@@ -126,6 +126,13 @@ if(FIXED_POINT_PROCESSOR)
+ 	add_definitions(-D__ARMEL__)
+ endif()
+ 
++if(CMAKE_SYSTEM_PROCESSOR STREQUAL "aarch64")
++	add_definitions(
++		-DWEBRTC_ARCH_ARM64
++		-DWEBRTC_HAS_NEON
++	)
++endif()
++
+ set(AEC_CXX11_FLAGS "-std=c++11")
+ 
+ set(WEBRTC_SIGNAL_PROCESSING_DIR ${WEBRTC_SRC_DIR}/common_audio/signal_processing)
+@@ -203,6 +210,11 @@ if(ENABLE_AEC)
+ 		list(APPEND AEC_SRCS
  			${AEC_SRC_DIR}/aec_core_sse2.c
  			${AEC_SRC_DIR}/aec_rdft_sse2.c
- 		)
++		)
 +		set_source_files_properties(
 +			${AEC_SRC_DIR}/aec_core_sse2.c
 +			${AEC_SRC_DIR}/aec_rdft_sse2.c
 +			PROPERTIES COMPILE_FLAGS "-msse2"
-+		)
+ 		)
  	endif()
  	include_directories(
- 		${AEC_SRC_DIR}/include