Revert "gpu: ion: Clarify variable names and comments around heap ids v types"

This reverts commit 96d395c4756d3731ebb9277393dc2db00e07d689.

Change-Id: Ie95719dadc2f6c3641a5bd97d5b24cb835802aff
Merge "Revert "gpu: ion: Clarify variable names and comments around heap ids v types"" into lollipop