msm: kgsl: Add struct kgsl_device to kgsl_allocate_contiguous API

We need to pass a non NULL struct device * for the call to
dma_alloc_coherent(). Change certain APIs to allow us to pass
down struct kgsl_device ptr so we can pass in a valid struct
device * to dma_alloc_coherent()

Change-Id: I24eaa2b7834b573b0520f6aa1f00447eb1f35dc6
Signed-off-by: Shrenuj Bansal <shrenujb@codeaurora.org>