rp2/CMakeLists.txt: Enable USB enumeration fix.

This is a workaround for errata RP2040-E5, and is needed to make USB more
reliable on certain USB ports.

Signed-off-by: Damien George <damien@micropython.org>

ports/rp2/CMakeLists.txt

@@ -170,6 +170,7 @@ target_compile_definitions(${MICROPY_TARGET} PRIVATE
     PICO_NO_PROGRAM_VERSION_STRING=1 # do it ourselves in main.c
     MICROPY_BUILD_TYPE="${CMAKE_C_COMPILER_ID} ${CMAKE_C_COMPILER_VERSION} ${CMAKE_BUILD_TYPE}"
     PICO_NO_BI_STDIO_UART=1 # we call it UART REPL
+    PICO_RP2040_USB_DEVICE_ENUMERATION_FIX=1
 )
 
 target_link_libraries(${MICROPY_TARGET}