platform: restructure (NuttX) architecture-specific code

updated: tone_alarm, px4io_serial, px4_micro_hal

cmake/px4_add_board.cmake

@@ -183,6 +183,9 @@ function(px4_add_board)
 	set(PX4_PLATFORM ${PLATFORM} CACHE STRING "PX4 board OS" FORCE)
 	list(APPEND CMAKE_MODULE_PATH ${PX4_SOURCE_DIR}/platforms/${PX4_PLATFORM}/cmake)
 
+	# platform-specific include path
+	include_directories(${PX4_SOURCE_DIR}/platforms/${PX4_PLATFORM}/src/px4/common/include)
+
 	if(ARCHITECTURE)
 		set(CMAKE_SYSTEM_PROCESSOR ${ARCHITECTURE} CACHE INTERNAL "system processor" FORCE)
 	endif()

cmake/px4_add_common_flags.cmake

@@ -174,6 +174,7 @@ function(px4_add_common_flags)
 		${PX4_BINARY_DIR}/src/lib
 		${PX4_BINARY_DIR}/src/modules
 
+		${PX4_SOURCE_DIR}/platforms/${PX4_PLATFORM}/src/px4/${PX4_CHIP_MANUFACTURER}/${PX4_CHIP}
 		${PX4_SOURCE_DIR}/src
 		${PX4_SOURCE_DIR}/src/include
 		${PX4_SOURCE_DIR}/src/lib

cmake/px4_add_library.cmake

@@ -40,7 +40,7 @@ include(px4_base)
 #	Like add_library but with PX4 platform dependencies
 #
 function(px4_add_library target)
-	add_library(${target} ${ARGN})
+	add_library(${target} EXCLUDE_FROM_ALL ${ARGN})
 
 	target_compile_definitions(${target} PRIVATE MODULE_NAME="${target}")