android-build: fix dricore build for autogenerated files (v3)

android-build: fix dricore build for autogenerated files (v3)

Recently more files were removed from control to be auto-generated
in the dricore library. Android build was not able to locate the
new files if they were not created beforehand.

LOCAL_SRC_FILES includes some of those files and Android.gen.mk
re-defines this variable by filtering out the auto-generated files.
Unfortunately for this variable it is not the same to have the SRCDIR
variable defined as the current directory.

By re-defining SRCDIR for the autotools build the Android build system
is happy again and the new files were actually removed from the sources
to use the auto generated versions.

Also patch d5c1801a018efda8ac2b was partially reverted as the files
can not be compiled to the LOCAL_PATH, instead they should live on the
intermediates folder so that a clean can wipe them out.

v3: [chad] Fix the definition of SRCDIR in libdricore/Makefile.am.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
Signed-off-by: Daniel Charles <daniel.charles@intel.com>