The IPC ops are optional, but they require that the ops struct is to be
allocated with all callbacks set to NULL.

Update the code to extend the optionality to:
sdev->ipc == NULL
sdev->ipc->ops == NULL
sdev->ipc->ops->[tplg] == NULL
sdev->ipc->ops->[tplg]->ops == NULL (treated optional currently)

At the same time standardize the naming of the ops pointer to tplg_ops
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Link: https://lore.kernel.org/r/20221221102328.9635-8-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>