ASoC: fsl: don't set link->platform if not needed

ASoC: fsl: don't set link->platform if not needed

imx_card_parse_of() allocs 2 components for CPU/Platform (A)

	static int imx_card_parse_of(...)
	{
		...
		for_each_child_of_node(...) {
			dlc = devm_kzalloc(...);
			...
			link->cpus	= &dlc[0];
(A)			link->platforms	= &dlc[1];
		}
		...
	}

The link might be used as DPCM backend, in such case, link->plaforms
will be not used. The driver overwrite it as Dummy DAI (B).

		} else if (!strncmp(link->name, "HiFi-ASRC-BE", 12)) {
			/* DPCM backend */
			link->no_pcm = 1;
			link->platforms->of_node = NULL;
(B)			link->platforms->name = "snd-soc-dummy";
		}

If it was not used for generic DMAEngine, we can just remove it.
By this patch, created dlc (A) will be just wasted, but it won't leak.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/87cydfr1z6.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>