If SMMU support is not available, fall back to programming the bypass
stream ID (0x7f).

Fixes: de5469c2 ("gpu: host1x: Program the channel stream ID")
Suggested-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
[treding@nvidia.com: rebase this on top of a later build fix]
Signed-off-by: Thierry Reding <treding@nvidia.com>