gpu: host1x: Don't skip assigning syncpoints to channels

[ Upstream commit eb258cc1fd458e584082be987dbc6ec42668c05e ]

The code to write the syncpoint channel assignment register
incorrectly skips the write if hypervisor registers are not available.

The register, however, is within the guest aperture so remove the
check and assign syncpoints properly even on virtualized systems.

Fixes: c3f52220 ("gpu: host1x: Enable Tegra186 syncpoint protection")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>