script to create PDK build tree from existing full source tree

- This sciript generate a mount_pdk.sh which will mount existing dirs to PDK dir using mount --bind
- After mount, PDK source tree looks like normal PDK source except the absence of .repo
- The PDK build directory can be used for PDK build, and changes made are transparent to both places
Example: pdk/build/prepare_pdk_tree.py ../tmp/pdk_build grouper tegra3 broadcom_wlan
         generates necessary dir under ../tmp/pdk_build with mount_pdk.sh and umount_pdk.sh
- mount_pdk.sh requires sudo, and once executed, all necessary sources are mounted.
- umount_pdk.sh unmounts mounted files
- This change also cleans old pdk build scripts which are not used any more.

Change-Id: I49c10be366a9a4c9eb28328ab2e57db1e592d2f4
10 files changed
tree: 7abaf1d94d4622a342bd8feeccfb30e65722b51d
  1. build/
  2. .gitignore