nuttx: Add Minimal support for stm32f7nucleo

[rzr]

So far, Only console, http module has been tested.

Config file is generated using defconfig, and contains those mandatory options:

CONFIG_NET_LOCAL=y
CONFIG_NET_TCPBACKLOG=y
CONFIG_PTHREAD_MUTEX_TYPES=y
CONFIG_RR_INTERVAL=100
CONFIG_SCHED_LPWORKPRIORITY=176

Build flags are relying on mcpu flags.

More IO modules to be supported next.

Relate-to: https://github.com/rzr/webthing-iotjs/issues/3 Change-Id: Ib44227e33c6b7d07f11687385d788017350e3827 IoT.js-DCO-1.0-Signed-off-by: Philippe Coval p.coval@samsung.com

[LaszloLango]

Please add a documentation like docs/build/Build-for-STM32F4-NuttX.md