gpu: host1x: Generalize host1x_cdma_push_wide()

host1x_cdma_push_wide() had the assumptions that the last parameter word
was a NOP opcode, and that NOP opcodes could be used in all situations.

Neither are true with the new job opcode sequence, so adjust the
function to not have these assumptions, and instead place an early
RESTART opcode when necessary to jump back to the beginning of the
pushbuffer.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>