Remove empty project platform/bootable/bootloader/legacy

BUG:19164048
Change-Id: Ib589b69b1c481d2040637f26f62f22c35ead5d5c

default.xml

@@ -14,7 +14,6 @@
   <project path="abi/cpp" name="platform/abi/cpp" groups="pdk" />
   <project path="art" name="platform/art" groups="pdk" />
   <project path="bionic" name="platform/bionic" groups="pdk" />
-  <project path="bootable/bootloader/legacy" name="platform/bootable/bootloader/legacy" groups="pdk-cw-fs" />
   <project path="bootable/recovery" name="platform/bootable/recovery" groups="pdk" />
   <project path="cts" name="platform/cts" groups="cts,pdk-cw-fs" />
   <project path="dalvik" name="platform/dalvik" groups="pdk-cw-fs" />