Bug 1331 - Generate SPIs and yangs to target/generated-sources/ subfolders

Instead of putting SPIs to target/generated-resources and yangs to target/yangs
use standard target-generated-sources/{spi,yang}
This change allows IDEs with auto detection capabilities to pick
up all resources that will be packaged into JAR with correct path.

Change-Id: If9f0367732baddf66e22135ccf3a59124455335f
Signed-off-by: Tomas Olvecky <tolvecky@cisco.com>
Merge "Bug 1331 - Generate SPIs and yangs to target/generated-sources/ subfolders"