ASoC: SOF: Fix function topology name check in profile info output

The function topology feature, and the plat_data->machine field that
specifies this feature, is ACPI specific. The check didn't take this
into consideration, which causes a NULL pointer dereference splat on
OF platforms:

BUG: KASAN: null-ptr-deref in sof_create_ipc_file_profile (sound/soc/sof/fw-file-profile.c:291 sound/soc/sof/fw-file-profile.c:340) snd_sof
Read of size 8 at addr 00000000000000c8 by task (udev-worker)/247

CPU: 7 UID: 0 PID: 247 Comm: (udev-worker) Not tainted 6.18.0-rc2-next-20251023-03804-g93b191bc0c26-dirty #747 PREEMPT ba3c303a11d89508de4087cb5b4f8985b6d87b6f
Hardware name: Google Ciri sku2 board (DT)
Call trace:
[KASAN stuff]
sof_create_ipc_file_profile (sound/soc/sof/fw-file-profile.c:291 sound/soc/sof/fw-file-profile.c:340) snd_sof
snd_sof_device_probe (sound/soc/sof/core.c:304 sound/soc/sof/core.c:388 sound/soc/sof/core.c:460 sound/soc/sof/core.c:719) snd_sof
sof_of_probe (sound/soc/sof/sof-of-dev.c:84) snd_sof_of
platform_probe (drivers/base/platform.c:1405)
[...]

Check that the ACPI specific field is actually valid before accessing
it.

This was seen on a MediaTek based Chromebook.

Fixes: 2b92b98cc476 ("ASoC: SOF: Don't print the monolithic topology name if function topology may be used")
Cc: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Acked-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://patch.msgid.link/20251023061226.1127345-1-wenst@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>