drm/vc4: Release runtime PM reference after binding V3D

drm/vc4: Release runtime PM reference after binding V3D

The vc4_v3d_bind() function acquires a runtime PM reference via
pm_runtime_resume_and_get() to access V3D registers during setup.
However, this reference is never released after a successful bind.
This prevents the device from ever runtime suspending, since the
reference count never reaches zero.

Release the runtime PM reference by adding pm_runtime_put_autosuspend()
after autosuspend is configured, allowing the device to runtime suspend
after the delay.

Fixes: 266cff37d7fc ("drm/vc4: v3d: Rework the runtime_pm setup")
Reviewed-by: Melissa Wen <mwen@igalia.com>
Link: https://patch.msgid.link/20260330-vc4-misc-fixes-v1-1-92defc940a29@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>