Support for simultaneous GPS and Spektrum satellite

Added support for simultaneuous GPS and Spektrum satellite (or
SBUS/SUMD):
- Features needed to enable: "Enable Serial-based receiver", "Enable 3rd
serial port" and Enable GPS
- Naze32 pins: Spektrum satellite RX pin 4. GPS TX pin 5 and GPS RX pin
6.
- GPS is using soft serial so it's maximum baud rate is 19200 (current
softserial implementation). Default baud rate is 9600, but it can be
changed from CLI with command set softserial_baudrate=19200. After setup
I recommend to power off for some time so that GPS will work.

Added more channels to Spektrum satellite:
- DSMX satellites (SPEKTRUM2048) support up to 8 channels.
- DSM2 satellites (SPEKTRUM1024) support up to 7 channels.
Added Spektrum satellite binding to transmitter

Possibility to bind Spektrum satellite with transmitter without need of
separate RX.

Instructions for attaching Spektrum satellite to Naze32:
- Grey signal wire to pin 4. (pins on the left side of the Naze32)
- Black wire to ground (e.g. pin above pin 4)
- Orange wire to 3V power pin. (next to leds)

Instructions to bind the satellite:
- Make sure that satellite has been connected correctly.
- Connect Naze32 to USB
- Open baseflight and connect to Naze32 (baseflight app in Chrome)
- From Configuration tab make sure that you have selected "Enable
Serial-based receiver" and Serial receiver is correct (e.g. SPEKTRM2048
for DSMX)
- From CLI tab type: "set spektrum_sat_bind = 9" for DSMX or "set
spektrum_sat_bind = 5" from DSM2
- type "save" and after Naze32 reboot remove USB cable (=Power off the
Naze32)
- Wait a sec and reconnect the USB cable. After cold start satellite led
should start blinking and transmitter should be turned on while pressing
the bind button.
- After binding satellite led should be solid. Connect baseflight and
use receiver tab to test that satellite is working correctly.
- Final step is to go to CLI tab and type "set spektrum_sat_bind = 0"
and then type "save". This must be done so that satellite doesn't go to
bind mode when Naze32 is repowered.
Revert "Added Spektrum satellite binding to transmitter"

This reverts commit 08493fa21205fda604739f0d63100e57ada93199.
Revert "Support for simultaneous GPS and Spektrum satellite"

This reverts commit 38d575718441fc17f45a7864bfa0baac8d4fc23b.
Spektrum DSMX satellite 8th channel support

Added support for 8th channel when using Spektrum DSMX satellite.
(old 1024 resolution 22ms DSM2 still work with 7 channels because those
doesn't support 8 channels)
Added Spektrum satellite binding to transmitter

Possibility to bind Spektrum satellite with transmitter without need of
separate RX.

Instructions for attaching Spektrum satellite to Naze32:
- Grey signal wire to pin 4. (pins on the left side of the Naze32)
- Black wire to ground (e.g. pin above pin 4)
- Orange wire to 3V power pin. (next to leds)

Instructions to bind the satellite:
- Make sure that satellite has been connected correctly.
- Connect Naze32 to USB
- Open baseflight and connect to Naze32 (baseflight app in Chrome)
- From Configuration tab make sure that you have selected "Enable
Serial-based receiver" and Serial receiver is correct (e.g. SPEKTRM2048
for DSMX)
- From CLI tab type: "set spektrum_sat_bind = 9" for DSMX or "set
spektrum_sat_bind = 5" from DSM2
- type "save" and after Naze32 reboot remove USB cable (=Power off the
Naze32)
- Wait a sec and reconnect the USB cable. After cold start satellite led
should start blinking and transmitter should be turned on while pressing
the bind button.
- After binding satellite led should be solid. Connect baseflight and
use receiver tab to test that satellite is working correctly.
- Final step is to go to CLI tab and type "set spektrum_sat_bind = 0"
and then type "save". This must be done so that satellite doesn't go
back to
binding mode when Naze32 is repowered again.
Formatting corrections

Corrected formatting.
Some more formating corrections

More formating fixes... hard to make it right when I am used to use
different formatting ;)
Merge pull request #181 from jaahaavi/master

Spektrum DSMX satellite 8th channel support