gpu: host1x: Request syncpoint IRQs only during probe

Syncpoint IRQs are currently requested in a code path that runs
during resume. Due to this, we get multiple overlapping registered
interrupt handlers as host1x is suspended and resumed.

Rearrange interrupt code to only request IRQs during initialization.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240531070719.2138-1-cyndis@kapsi.fi