esp32: Enable btree module.

This was disabled with the move to CMake, and this commit reinstates it.
Signed-off-by: Damien George <damien@micropython.org>

ports/esp32/main/CMakeLists.txt

@@ -149,6 +149,7 @@ set(MICROPY_CROSS_FLAGS -march=xtensawin)
 
 # Set compile options for this port.
 target_compile_definitions(${MICROPY_TARGET} PUBLIC
+    ${MICROPY_DEF_CORE}
     MICROPY_ESP_IDF_4=1
     MICROPY_VFS_FAT=1
     MICROPY_VFS_LFS2=1
@@ -164,7 +165,8 @@ target_compile_options(${MICROPY_TARGET} PUBLIC
     -Wno-missing-field-initializers
 )
 
-# add usermod
+# Add additional extmod and usermod components.
+target_link_libraries(${MICROPY_TARGET} micropy_extmod_btree)
 target_link_libraries(${MICROPY_TARGET} usermod)
 
 

ports/esp32/mpconfigport.h

@@ -162,6 +162,7 @@
 #define MICROPY_PY_UWEBSOCKET               (1)
 #define MICROPY_PY_WEBREPL                  (1)
 #define MICROPY_PY_FRAMEBUF                 (1)
+#define MICROPY_PY_BTREE                    (1)
 #define MICROPY_PY_USOCKET_EVENTS           (MICROPY_PY_WEBREPL)
 #define MICROPY_PY_BLUETOOTH_RANDOM_ADDR    (1)
 #define MICROPY_PY_BLUETOOTH_DEFAULT_GAP_NAME ("ESP32")