Move the sdk project to a subdir.

Signed-off-by: jmug <u.g.a.mariano@gmail.com>

with_sdk/rp2350/blink/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.13...3.27)
+
+# initialize pico-sdk from submodule
+# note: this must happen before project()
+include(../../../pico-sdk/pico_sdk_init.cmake)
+
+project(my_project)
+
+# initialize the Raspberry Pi Pico SDK
+set(PICO_BOARD, "pico")
+pico_sdk_init()
+
+# rest of your project
+add_executable(hello_world
+    hello_world.c
+    led.s
+)
+
+# Add pico_stdlib library which aggregates commonly used features
+target_link_libraries(hello_world pico_stdlib)
+
+# create map/bin/hex/uf2 file in addition to ELF.
+pico_add_extra_outputs(hello_world)