Add support to build for rp2 using cmake.

The changes are not specific to rp2. cmake support was added and
the rp2 port of micropython only works with cmake.

README.md

@@ -42,6 +42,15 @@ And then compile the module with specified USER_C_MODULES dir
     $ make USER_C_MODULES=../../../st7789_mpy/ all
 
 
+For rp2040 (requires micropython 1.15):
+
+    $ cd micropython/ports/rp2
+
+And then compile the module with specified USER_C_MODULES dir
+
+    $ make USER_C_MODULES=../../../st7789_mpy/st7789/micropython.cmake all
+
+
 If you have other user modules, copy the st7789_driver/st7789 to
 the user modules directory
 

st7789/micropython.cmake

@@ -0,0 +1,11 @@
+add_library(usermod_st7789 INTERFACE)
+
+target_sources(usermod_st7789 INTERFACE
+    ${CMAKE_CURRENT_LIST_DIR}/st7789.c
+)
+
+target_include_directories(usermod_st7789 INTERFACE
+    ${CMAKE_CURRENT_LIST_DIR}
+)
+
+target_link_libraries(usermod INTERFACE usermod_st7789)

st7789/micropython.mk

@@ -2,5 +2,5 @@ ST7789_MOD_DIR := $(USERMOD_DIR)
 SRC_USERMOD += $(addprefix $(ST7789_MOD_DIR)/, \
 	st7789.c \
 )
-CFLAGS_USERMOD += -I$(ST7789_MOD_DIR) -DMODULE_ST7789_ENABLED=1
+CFLAGS_USERMOD += -I$(ST7789_MOD_DIR)
 # CFLAGS_USERMOD += -DEXPOSE_EXTRA_METHODS=1

st7789/st7789.c

@@ -663,4 +663,4 @@ const mp_obj_module_t mp_module_st7789 = {
     .globals = (mp_obj_dict_t*)&mp_module_st7789_globals,
 };
 
-MP_REGISTER_MODULE(MP_QSTR_st7789, mp_module_st7789, MODULE_ST7789_ENABLED);
+MP_REGISTER_MODULE(MP_QSTR_st7789, mp_module_st7789, 1);