Use cJSON to get the GPIO definitions

In gpio_init, read the GPIO definitions out of the JSON
instead of D-Bus.

As many applications configure several GPIOs at once, the
cJSON structure for the GPIOs stays loaded in memory until
explicitly freed by calling gpio_inits_done().

Change-Id: I3ba216545a4a367744ce1fac09ca19c4d8d9d302
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
2 files changed