PIOS COM: make the interface thread safe

Currently the interface to the FIFO buffer is not thread
safe for multiple threads sending and receiving. This adds
a semaphore on those interfaces.
Android: add serial support for FTDI_FT230X

This is the chipset used in the 3dr radio v2 and should
add support for that radio.
Merge pull request #1187 from peabody124/ftdi_pid

Android: add serial support for FTDI_FT230X
Merge pull request #1181 from peabody124/pios_com_thread

PIOS COM: make the interface thread safe
LSM9DS1: add initial version

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
Fix code style using Lindent script

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
LSM9DS1: add allocate function.

This must be squashed before merge request.

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
LSM9DS1: first release.

This commit must be squashed after the needed check on driver
functionality.

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
LSM9DS1: add probe function.

Add probe function to check if the device exist on selected
i2c bus.

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
LSM9DS1: configure interrupt source using the faster sensor.

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
LSM9DS1: final release before testing.

Added some register configuration missed in the previous
version.

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>