ion: Convert allocation counters to long

On 64bit platforms, the amount of memory allocated by ion can exceed
32 bits.  Therefore the counters which track this information must be
64 bits as well.

Change-Id: I81daf2cec78de5787279daaf98264c5462ba6645
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>