[nostalgia] Break part of core out into Turbine and TeaGBA libraries

src/turbine/gba/CMakeLists.txt

@@ -0,0 +1,16 @@
+enable_language(CXX ASM)
+set_source_files_properties(turbine.arm.cpp irq.arm.cpp PROPERTIES COMPILE_FLAGS -marm)
+target_sources(
+	Turbine PRIVATE
+		clipboard.cpp
+		gfx.cpp
+		irq.arm.cpp
+		irq.s
+		turbine.arm.cpp
+		turbine.cpp
+)
+
+target_link_libraries(
+	Turbine PUBLIC
+		TeaGBA
+)