msm: kgsl: Remove bitfields from HFI communications

Bitfields are fine in the correct situation. This is not one of them.
The CPU and GMU could be compiled differently so rather than
hope that everything works out between the commands passed between
processors, use shifts and masks to ensure data is transferred
as expected.

Change-Id: I44bc06c235fae9239d968f91db536281600d3fe8
Signed-off-by: Oleg Perelet <operelet@codeaurora.org>
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>