Tools: add PilotPi support

Adds "pilotpi" board to support https://docs.px4.io/main/en/flight_controller/raspberry_pi_pilotpi.html

Tools/ardupilotwaf/boards.py

@@ -1658,6 +1658,15 @@ class canzero(linux):
             CONFIG_HAL_BOARD_SUBTYPE = 'HAL_BOARD_SUBTYPE_LINUX_CANZERO',
         )
         
+class pilotpi(linux):
+    toolchain = 'aarch64-linux-gnu'
+
+    def configure_env(self, cfg, env):
+        super(pilotpi, self).configure_env(cfg, env)
+        env.DEFINES.update(
+            CONFIG_HAL_BOARD_SUBTYPE = 'HAL_BOARD_SUBTYPE_LINUX_PILOTPI',
+        )
+
 class SITL_static(sitl):
     def configure_env(self, cfg, env):
         super(SITL_static, self).configure_env(cfg, env)

Tools/scripts/board_list.py

@@ -71,6 +71,7 @@ class BoardList(object):
             Board("blue"),
             Board("pxfmini"),
             Board("canzero"),
+            Board("pilotpi"),
             Board("SITL_x86_64_linux_gnu"),
             Board("SITL_arm_linux_gnueabihf"),
         ]