Remove ALL_GENERATED_SOURCES

ALL_GENERATED_SOURCES contains the generated sources of modules
defined in Make.  They always have a path inside the intermediates
directories.  The only readers of ALL_GENERATED_SOURCES are filtering
for files in the output directories, and will never match anything.

Test: m checkbuild
Change-Id: Ic9af8761d445fa90088f838c385bd2aea3bc3048