staging: android: ion: Remove file ion_chunk_heap.c

Remove file ion_chunk_heap.c as its functions and definitions are not
used anywhere else.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Link: https://lore.kernel.org/r/20190703081842.22872-2-nishkadg.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>