Have the yaml_list now have 'node', 'bus', and 'compat' information
instead of just the 'node' info. For now we have all YAML nodes under
yaml_list['node'], however this will change to support sensors that
can be on I2C or SPI, since they will have the same compat, but
different YAML nodes.
This also introduces yaml_list['bus'] which has YAML nodes for any
compatiables on a given 'parent' bus (ie, 'i2c', or 'spi').
Finally, we also have yaml_list['compat'] with all the compatiables
that we parsed and matched to a YAML.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>