zephyr: Update GOOGLE_RTC_AUDIO_PROCESSING

Unbreak the Zephyr build when this is enabled, and add the needed bits
to produce a working executable.

This is mostly just a recapitulation of the existing integration,
which means that it's manually pulling in bits from the Cadence
toolchain it needs.  SOF isn't yet using the Zephyr C++ integration
(which isn't xt-clang aware yet), nor does it really want to as SOF
itself includes no such code.  Zephyr doesn't have a "C++ binary
linkage only" feature yet.

Signed-off-by: Andy Ross <andyross@google.com>

zephyr/CMakeLists.txt

@@ -877,6 +877,17 @@ zephyr_library_sources_ifdef(CONFIG_SOF_BOOT_TEST
        boot_test.c
 )
 
+if(CONFIG_COMP_GOOGLE_RTC_AUDIO_PROCESSING AND NOT CONFIG_GOOGLE_RTC_AUDIO_PROCESSING_MOCK)
+	zephyr_include_directories(../third_party/include)
+	target_link_directories(SOF INTERFACE ../third_party/lib)
+	target_link_libraries(SOF INTERFACE google_rtc_audio_processing)
+	target_link_libraries(SOF INTERFACE c++)
+	target_link_libraries(SOF INTERFACE c++abi)
+	target_link_libraries(SOF INTERFACE m)
+	target_link_libraries(SOF INTERFACE c)
+	target_link_libraries(SOF INTERFACE gcc)
+endif()
+
 zephyr_library_link_libraries(SOF)
 target_link_libraries(SOF INTERFACE zephyr_interface)