Add ~empty implementation of HAL for pico2

src/avclan/target/pico2/CMakeLists.txt

@@ -0,0 +1,32 @@
+list(APPEND PICO_CONFIG_HEADER_FILES ${CMAKE_CURRENT_LIST_DIR}/pimoroni_pico_plus2w_rp2350.h)
+pico_sdk_init()
+
+target_sources(avclan PRIVATE
+    phy.cc
+    media.cc
+    cd_timer.cc
+    board.cc
+    stdio.cc
+    )
+
+target_link_libraries(avclan PUBLIC
+    pico_stdlib pico_stdio_usb
+)
+
+add_executable(mockingboard_pico
+    ${avclan-mockingboard_SOURCE_DIR}/src/sniffer.cc
+)
+target_link_libraries(mockingboard_pico PUBLIC
+    avclan
+)
+
+# Silence warnings in TinyUSB, and only there.
+file(GLOB_RECURSE _tinyusb_sources ${PICO_TINYUSB_PATH}/src/*.c)
+set_source_files_properties(${_tinyusb_sources}
+    TARGET_DIRECTORY avclan mockingboard_pico
+    PROPERTIES COMPILE_OPTIONS "-w")
+unset(_tinyusb_sources)
+
+pico_add_extra_outputs(mockingboard_pico)
+pico_set_float_implementation(mockingboard_pico none)
+pico_set_double_implementation(mockingboard_pico none)