accel/ivpu: Update last_busy in IRQ handler

Call pm_runtime_mark_last_busy() in top half of IRQ handler to prevent
device from being runtime suspended before bottom half is executed on
a workqueue.

Reviewed-by: Karol Wachowski <karol.wachowski@intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250129125636.1047413-3-jacek.lawrynowicz@linux.intel.com