Add Spresense board support

[Barry-Xu-2018]

No description provided.

[Acuadros95]

Hello, just two comments:

• We didn't expect modifications on the micro_ros_setup general scripts (build_firmware.sh, configure_firmware.sh ...) did you encounter problems with them?
• It could be more interesting to integrate your board on the new micro-ROS Nuttx app, which is not related to micro_ros_setup.

[Barry-Xu-2018]

@Acuadros95

Thanks for your comments.

• We didn't expect modifications on the micro_ros_setup general scripts (build_firmware.sh, configure_firmware.sh ...) did you encounter problems with them?

Yes. I understand. These scrips (build_firmware.sh, etc) should not be modified.
But current logic of codes is a little confused to me. So I modify it and want to discuss it with reviewer.
e.g.

micro_ros_setup/scripts/build_firmware.sh

Lines 72 to 76 in 720350f

	if [ $PLATFORM != "generic" ] && [ -d "$PREFIX/config/$RTOS/generic" ]; then
	. $PREFIX/config/$RTOS/generic/build.sh
	else
	. $PREFIX/config/$RTOS/$PLATFORM/build.sh
	fi

generic directory put common scripts which may be used for different platform.
$PLATFORM directory put special scripts which is only for this platform.
Naturally，if build.sh exist in $PLATFORM directory, this script should be used instead of flash.sh in generic directory.
Current logic is if flash.sh exists in generic directory, it should be used. If I want to special operations in flash.sh for my platform, how to do ? (generic directory should be removed ?)

• It could be more interesting to integrate your board on the new micro-ROS Nuttx app, which is not related to micro_ros_setup.

I know you plan to remove official support to NuttX in micro-ROS Galactic. So foxy version also don't want to add any change for NuttX. Right ?

[Acuadros95]

Yes, you are right, $PLATFORM directory should be preferred over generic. I will check that these changes don't affect the rest of the available platforms.

And we will keep supporting NuttX on foxy, so feel free to include your port into this version. But in the future, only the new app will be used.

[Barry-Xu-2018]

Yes, you are right, $PLATFORM directory should be preferred over generic. I will check that these changes don't affect the rest of the available platforms.

Okay. Thank you.

And we will keep supporting NuttX on foxy, so feel free to include your port into this version. But in the future, only the new app will be used.

Get it.

[fujitatomoya]

Nit:

Suggested change

	| Spresense | WiFi | - | - |
	| Spresense | Network | - | - |

[fujitatomoya]

Nit:

Suggested change

	# spresense use own sdk to config
	# spresense uses own sdk to config

[fujitatomoya]

Suggested change

	<maintainer email="[email protected].com">Ingo Luetkebohle</maintainer>
	<maintainer email="Barry.Xu@sony.com">Barry Xu</maintainer>
	<maintainer email="[email protected]">Tomoya Fujita</maintainer>

[Barry-Xu-2018]

@fujitatomoya

Thanks for your review comments. I have addressed them at 4184ad9.