Initial callisto support (second try)

* Used tass LDPI repository as reference for initial commit
* Override BOARD_BML_BOOT and BOARD_BML_RECOVERY to use proper
  partitions (bml9 and bml10, respectively)
* Install custom parts.rc to ensure that proper Bluetooth firmware
  is used (BCM2049B0)

Change-Id: Ic345c03ad37e7895881ec79734c0ba87cc793a88