accel/ivpu: Check return code of ipc->lock init

Return value of drmm_mutex_init(ipc->lock) was unchecked.

Fixes: 5d7422cf ("accel/ivpu: Add IPC driver and JSM messages")
Cc: <stable@vger.kernel.org> # v6.3+
Signed-off-by: Wachowski, Karol <karol.wachowski@intel.com>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402104929.941186-2-jacek.lawrynowicz@linux.intel.com