staging: android: ion: Remove ion_handle and ion_client

staging: android: ion: Remove ion_handle and ion_client

ion_handle was introduced as an abstraction to represent a reference to
a buffer via an ion_client. As frameworks outside of Ion evolved, the dmabuf
emerged as the preferred standard for use in the kernel. This has made
the ion_handle an unnecessary abstraction and prone to race
conditions. ion_client is also now only used internally. We have enough
mechanisms for race conditions and leaks already so just drop ion_handle
and ion_client. This also includes ripping out most of the debugfs
infrastructure since much of that was tied to clients and handles.
The debugfs infrastructure was prone to give confusing data (orphaned
allocations) so it can be replaced with something better if people
actually want it.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>