The variable MANGOH_I2C_BUS_BATTERY has been introduced in the targets
files for 9x15 and 9x07 because the I2C bus numbering differs.  The
batteryService app has been updated to use this variable.

In this version the app model and adef have matching version numbers
(2.0)

The battery gauge was disabled on wp76/77 because of a lockup in the
power supply kernel subsystem when the battery gauge driver was
unloaded.  This has been fixed in release 8 and thus the battery gauge
driver and battery service can be enabled.  The battery gauge and
battery service still aren't usable on wp75/85 because of a different
kernel bug.

Added script used to configure the MangOH to route to/from
local LAN interface, i.e. eth0 to/from the cellular WAN interface,
i.e. rmnet-data0.

The mangOH makefile now reads a $LEGATO variable to decide if the Legato
framework at $LEGATO_ROOT should be built.  Previously, but variable
$NO_BUILD_LEGATO was used, but this was a bit verbose.

Also support building of multiple targets with correct toolchains with
one invocation of make.

Introduce a single mangOH.sdef and remove the board/module specific
SDEFs.  The content of the single SDEF change depending on the build
parameters.  The "targets" directory was introduced based on the way
Legato handles different modules.  The location of build artifacts has
now changed.  Everything produced by the Makefile is under "build/".

The IoT slot driver has been disabled due to conflicts between it and
the way that the GPIOs for the WiFi IoT card are being configured by the
default yocto linux image.

Added the new Linux device driver for the card detect LED and
added a LED service with an API to set/get the LED status.

Removed kfree calls to free the slot memory.  The use of
devm_ calls to create the memory removes the need to call
kfree.

This member does not need to be persisted as it can simply be returned
to the caller requesting the mailbox value.