msm: kgsl: Check for secure alignment after importing the buffer

The param->length parameter isn't used when importing dma-buf buffers
so checking it for alignment in the secure buffer case is silly. We
do need to check for alignment but do it after the import when we
know the actual size of the buffer.

Change-Id: Ic0dedbadd0b5488968c3b2aab74973ca93235f5e
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>