arm64: Warn on NULL device structure for dma APIs

Although parts of the DMA apis may properly check for NULL devices,
there may be some places that don't. Rather than fix up all the
possible locations, just require a non-NULL device structure to be
used for allocating/freeing.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[catalin.marinas@arm.com: s/WARN/WARN_ONCE/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Git-commit: c666e8d5cae745b1515898f8b7a033c468a899d0
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


[imaund@codeaurora.org: Maintain Catalin's substitution]
Signed-off-by: Ian Maund <imaund@codeaurora.org>