move Debug to platforms/nuttx

platforms/nuttx/Debug/openocd.gdbinit

@@ -0,0 +1,21 @@
+target remote :3333
+
+# Don't let GDB get confused while stepping
+define hook-step
+  mon cortex_m maskisr on
+end
+define hookpost-step
+  mon cortex_m maskisr off
+end
+
+mon init
+mon stm32_init
+# mon reset halt
+mon poll
+mon cortex_m maskisr auto
+set mem inaccessible-by-default off
+set print pretty
+source platforms/nuttx/Debug/PX4
+
+echo PX4 resumed, press ctrl-c to interrupt\n
+continue